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 if (unlikely(virtqueue_is_broken(vq))) 192 break; 193 } while (!virtqueue_enable_cb(vq)); 194 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 195 } 196 197 static void virtscsi_req_done(struct virtqueue *vq) 198 { 199 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 200 struct virtio_scsi *vscsi = shost_priv(sh); 201 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 202 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 203 204 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 205 }; 206 207 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 208 { 209 int i, num_vqs; 210 211 num_vqs = vscsi->num_queues; 212 for (i = 0; i < num_vqs; i++) 213 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 214 virtscsi_complete_cmd); 215 } 216 217 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 218 { 219 struct virtio_scsi_cmd *cmd = buf; 220 221 if (cmd->comp) 222 complete(cmd->comp); 223 } 224 225 static void virtscsi_ctrl_done(struct virtqueue *vq) 226 { 227 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 228 struct virtio_scsi *vscsi = shost_priv(sh); 229 230 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 231 }; 232 233 static void virtscsi_handle_event(struct work_struct *work); 234 235 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 236 struct virtio_scsi_event_node *event_node) 237 { 238 int err; 239 struct scatterlist sg; 240 unsigned long flags; 241 242 INIT_WORK(&event_node->work, virtscsi_handle_event); 243 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 244 245 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 246 247 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 248 GFP_ATOMIC); 249 if (!err) 250 virtqueue_kick(vscsi->event_vq.vq); 251 252 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 253 254 return err; 255 } 256 257 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 258 { 259 int i; 260 261 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 262 vscsi->event_list[i].vscsi = vscsi; 263 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 264 } 265 266 return 0; 267 } 268 269 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 270 { 271 int i; 272 273 /* Stop scheduling work before calling cancel_work_sync. */ 274 spin_lock_irq(&vscsi->event_vq.vq_lock); 275 vscsi->stop_events = true; 276 spin_unlock_irq(&vscsi->event_vq.vq_lock); 277 278 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 279 cancel_work_sync(&vscsi->event_list[i].work); 280 } 281 282 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 283 struct virtio_scsi_event *event) 284 { 285 struct scsi_device *sdev; 286 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 287 unsigned int target = event->lun[1]; 288 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 289 290 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 291 case VIRTIO_SCSI_EVT_RESET_RESCAN: 292 if (lun == 0) { 293 scsi_scan_target(&shost->shost_gendev, 0, target, 294 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 295 } else { 296 scsi_add_device(shost, 0, target, lun); 297 } 298 break; 299 case VIRTIO_SCSI_EVT_RESET_REMOVED: 300 sdev = scsi_device_lookup(shost, 0, target, lun); 301 if (sdev) { 302 scsi_remove_device(sdev); 303 scsi_device_put(sdev); 304 } else { 305 pr_err("SCSI device %d 0 %d %d not found\n", 306 shost->host_no, target, lun); 307 } 308 break; 309 default: 310 pr_info("Unsupported virtio scsi event reason %x\n", event->reason); 311 } 312 } 313 314 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 315 struct virtio_scsi_event *event) 316 { 317 struct scsi_device *sdev; 318 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 319 unsigned int target = event->lun[1]; 320 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 321 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 322 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 323 324 sdev = scsi_device_lookup(shost, 0, target, lun); 325 if (!sdev) { 326 pr_err("SCSI device %d 0 %d %d not found\n", 327 shost->host_no, target, lun); 328 return; 329 } 330 331 /* Handle "Parameters changed", "Mode parameters changed", and 332 "Capacity data has changed". */ 333 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 334 scsi_rescan_device(sdev); 335 336 scsi_device_put(sdev); 337 } 338 339 static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 340 { 341 struct scsi_device *sdev; 342 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 343 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 344 int result, inquiry_len, inq_result_len = 256; 345 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 346 347 if (!inq_result) 348 return -ENOMEM; 349 350 shost_for_each_device(sdev, shost) { 351 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 352 353 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 354 scsi_cmd[0] = INQUIRY; 355 scsi_cmd[4] = (unsigned char) inquiry_len; 356 357 memset(inq_result, 0, inq_result_len); 358 359 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 360 inq_result, inquiry_len, 361 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 362 363 if (result == 0 && inq_result[0] >> 5) { 364 /* PQ indicates the LUN is not attached */ 365 scsi_remove_device(sdev); 366 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 367 /* 368 * If all LUNs of a virtio-scsi device are unplugged 369 * it will respond with BAD TARGET on any INQUIRY 370 * command. 371 * Remove the device in this case as well. 372 */ 373 scsi_remove_device(sdev); 374 } 375 } 376 377 kfree(inq_result); 378 return 0; 379 } 380 381 static void virtscsi_handle_event(struct work_struct *work) 382 { 383 struct virtio_scsi_event_node *event_node = 384 container_of(work, struct virtio_scsi_event_node, work); 385 struct virtio_scsi *vscsi = event_node->vscsi; 386 struct virtio_scsi_event *event = &event_node->event; 387 388 if (event->event & 389 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 390 int ret; 391 392 event->event &= ~cpu_to_virtio32(vscsi->vdev, 393 VIRTIO_SCSI_T_EVENTS_MISSED); 394 ret = virtscsi_rescan_hotunplug(vscsi); 395 if (ret) 396 return; 397 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 398 } 399 400 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 401 case VIRTIO_SCSI_T_NO_EVENT: 402 break; 403 case VIRTIO_SCSI_T_TRANSPORT_RESET: 404 virtscsi_handle_transport_reset(vscsi, event); 405 break; 406 case VIRTIO_SCSI_T_PARAM_CHANGE: 407 virtscsi_handle_param_change(vscsi, event); 408 break; 409 default: 410 pr_err("Unsupported virtio scsi event %x\n", event->event); 411 } 412 virtscsi_kick_event(vscsi, event_node); 413 } 414 415 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 416 { 417 struct virtio_scsi_event_node *event_node = buf; 418 419 if (!vscsi->stop_events) 420 queue_work(system_freezable_wq, &event_node->work); 421 } 422 423 static void virtscsi_event_done(struct virtqueue *vq) 424 { 425 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 426 struct virtio_scsi *vscsi = shost_priv(sh); 427 428 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 429 }; 430 431 static int __virtscsi_add_cmd(struct virtqueue *vq, 432 struct virtio_scsi_cmd *cmd, 433 size_t req_size, size_t resp_size) 434 { 435 struct scsi_cmnd *sc = cmd->sc; 436 struct scatterlist *sgs[6], req, resp; 437 struct sg_table *out, *in; 438 unsigned out_num = 0, in_num = 0; 439 440 out = in = NULL; 441 442 if (sc && sc->sc_data_direction != DMA_NONE) { 443 if (sc->sc_data_direction != DMA_FROM_DEVICE) 444 out = &sc->sdb.table; 445 if (sc->sc_data_direction != DMA_TO_DEVICE) 446 in = &sc->sdb.table; 447 } 448 449 /* Request header. */ 450 sg_init_one(&req, &cmd->req, req_size); 451 sgs[out_num++] = &req; 452 453 /* Data-out buffer. */ 454 if (out) { 455 /* Place WRITE protection SGLs before Data OUT payload */ 456 if (scsi_prot_sg_count(sc)) 457 sgs[out_num++] = scsi_prot_sglist(sc); 458 sgs[out_num++] = out->sgl; 459 } 460 461 /* Response header. */ 462 sg_init_one(&resp, &cmd->resp, resp_size); 463 sgs[out_num + in_num++] = &resp; 464 465 /* Data-in buffer */ 466 if (in) { 467 /* Place READ protection SGLs before Data IN payload */ 468 if (scsi_prot_sg_count(sc)) 469 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 470 sgs[out_num + in_num++] = in->sgl; 471 } 472 473 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 474 } 475 476 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 477 { 478 bool needs_kick; 479 unsigned long flags; 480 481 spin_lock_irqsave(&vq->vq_lock, flags); 482 needs_kick = virtqueue_kick_prepare(vq->vq); 483 spin_unlock_irqrestore(&vq->vq_lock, flags); 484 485 if (needs_kick) 486 virtqueue_notify(vq->vq); 487 } 488 489 /** 490 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 491 * @vq : the struct virtqueue we're talking about 492 * @cmd : command structure 493 * @req_size : size of the request buffer 494 * @resp_size : size of the response buffer 495 * @kick : whether to kick the virtqueue immediately 496 */ 497 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 498 struct virtio_scsi_cmd *cmd, 499 size_t req_size, size_t resp_size, 500 bool kick) 501 { 502 unsigned long flags; 503 int err; 504 bool needs_kick = false; 505 506 spin_lock_irqsave(&vq->vq_lock, flags); 507 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 508 if (!err && kick) 509 needs_kick = virtqueue_kick_prepare(vq->vq); 510 511 spin_unlock_irqrestore(&vq->vq_lock, flags); 512 513 if (needs_kick) 514 virtqueue_notify(vq->vq); 515 return err; 516 } 517 518 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 519 struct virtio_scsi_cmd_req *cmd, 520 struct scsi_cmnd *sc) 521 { 522 cmd->lun[0] = 1; 523 cmd->lun[1] = sc->device->id; 524 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 525 cmd->lun[3] = sc->device->lun & 0xff; 526 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 527 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 528 cmd->prio = 0; 529 cmd->crn = 0; 530 } 531 532 #ifdef CONFIG_BLK_DEV_INTEGRITY 533 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 534 struct virtio_scsi_cmd_req_pi *cmd_pi, 535 struct scsi_cmnd *sc) 536 { 537 struct request *rq = scsi_cmd_to_rq(sc); 538 struct blk_integrity *bi; 539 540 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 541 542 if (!rq || !scsi_prot_sg_count(sc)) 543 return; 544 545 bi = blk_get_integrity(rq->q->disk); 546 547 if (sc->sc_data_direction == DMA_TO_DEVICE) 548 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 549 bio_integrity_bytes(bi, 550 blk_rq_sectors(rq))); 551 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 552 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 553 bio_integrity_bytes(bi, 554 blk_rq_sectors(rq))); 555 } 556 #endif 557 558 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 559 struct scsi_cmnd *sc) 560 { 561 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc)); 562 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 563 564 return &vscsi->req_vqs[hwq]; 565 } 566 567 static int virtscsi_queuecommand(struct Scsi_Host *shost, 568 struct scsi_cmnd *sc) 569 { 570 struct virtio_scsi *vscsi = shost_priv(shost); 571 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 572 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 573 bool kick; 574 unsigned long flags; 575 int req_size; 576 int ret; 577 578 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 579 580 /* TODO: check feature bit and fail if unsupported? */ 581 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 582 583 dev_dbg(&sc->device->sdev_gendev, 584 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 585 586 cmd->sc = sc; 587 588 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 589 590 #ifdef CONFIG_BLK_DEV_INTEGRITY 591 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 592 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 593 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 594 req_size = sizeof(cmd->req.cmd_pi); 595 } else 596 #endif 597 { 598 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 599 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 600 req_size = sizeof(cmd->req.cmd); 601 } 602 603 kick = (sc->flags & SCMD_LAST) != 0; 604 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 605 if (ret == -EIO) { 606 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 607 spin_lock_irqsave(&req_vq->vq_lock, flags); 608 virtscsi_complete_cmd(vscsi, cmd); 609 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 610 } else if (ret != 0) { 611 return SCSI_MLQUEUE_HOST_BUSY; 612 } 613 return 0; 614 } 615 616 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 617 { 618 DECLARE_COMPLETION_ONSTACK(comp); 619 int ret = FAILED; 620 621 cmd->comp = ∁ 622 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 623 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 624 goto out; 625 626 wait_for_completion(&comp); 627 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 628 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 629 ret = SUCCESS; 630 631 /* 632 * The spec guarantees that all requests related to the TMF have 633 * been completed, but the callback might not have run yet if 634 * we're using independent interrupts (e.g. MSI). Poll the 635 * virtqueues once. 636 * 637 * In the abort case, scsi_done() will do nothing, because the 638 * command timed out and hence SCMD_STATE_COMPLETE has been set. 639 */ 640 virtscsi_poll_requests(vscsi); 641 642 out: 643 mempool_free(cmd, virtscsi_cmd_pool); 644 return ret; 645 } 646 647 static int virtscsi_device_reset(struct scsi_cmnd *sc) 648 { 649 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 650 struct virtio_scsi_cmd *cmd; 651 652 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 653 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 654 if (!cmd) 655 return FAILED; 656 657 memset(cmd, 0, sizeof(*cmd)); 658 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 659 .type = VIRTIO_SCSI_T_TMF, 660 .subtype = cpu_to_virtio32(vscsi->vdev, 661 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 662 .lun[0] = 1, 663 .lun[1] = sc->device->id, 664 .lun[2] = (sc->device->lun >> 8) | 0x40, 665 .lun[3] = sc->device->lun & 0xff, 666 }; 667 return virtscsi_tmf(vscsi, cmd); 668 } 669 670 static int virtscsi_device_alloc(struct scsi_device *sdevice) 671 { 672 /* 673 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 674 * may have transfer limits which come from the host SCSI 675 * controller or something on the host side other than the 676 * target itself. 677 * 678 * To make this work properly, the hypervisor can adjust the 679 * target's VPD information to advertise these limits. But 680 * for that to work, the guest has to look at the VPD pages, 681 * which we won't do by default if it is an SPC-2 device, even 682 * if it does actually support it. 683 * 684 * So, set the blist to always try to read the VPD pages. 685 */ 686 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 687 688 return 0; 689 } 690 691 692 /** 693 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 694 * @sdev: Virtscsi target whose queue depth to change 695 * @qdepth: New queue depth 696 */ 697 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 698 { 699 struct Scsi_Host *shost = sdev->host; 700 int max_depth = shost->cmd_per_lun; 701 702 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 703 } 704 705 static int virtscsi_abort(struct scsi_cmnd *sc) 706 { 707 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 708 struct virtio_scsi_cmd *cmd; 709 710 scmd_printk(KERN_INFO, sc, "abort\n"); 711 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 712 if (!cmd) 713 return FAILED; 714 715 memset(cmd, 0, sizeof(*cmd)); 716 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 717 .type = VIRTIO_SCSI_T_TMF, 718 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 719 .lun[0] = 1, 720 .lun[1] = sc->device->id, 721 .lun[2] = (sc->device->lun >> 8) | 0x40, 722 .lun[3] = sc->device->lun & 0xff, 723 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 724 }; 725 return virtscsi_tmf(vscsi, cmd); 726 } 727 728 static void virtscsi_map_queues(struct Scsi_Host *shost) 729 { 730 struct virtio_scsi *vscsi = shost_priv(shost); 731 int i, qoff; 732 733 for (i = 0, qoff = 0; i < shost->nr_maps; i++) { 734 struct blk_mq_queue_map *map = &shost->tag_set.map[i]; 735 736 map->nr_queues = vscsi->io_queues[i]; 737 map->queue_offset = qoff; 738 qoff += map->nr_queues; 739 740 if (map->nr_queues == 0) 741 continue; 742 743 /* 744 * Regular queues have interrupts and hence CPU affinity is 745 * defined by the core virtio code, but polling queues have 746 * no interrupts so we let the block layer assign CPU affinity. 747 */ 748 if (i == HCTX_TYPE_POLL) 749 blk_mq_map_queues(map); 750 else 751 blk_mq_virtio_map_queues(map, vscsi->vdev, 2); 752 } 753 } 754 755 static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) 756 { 757 struct virtio_scsi *vscsi = shost_priv(shost); 758 struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num]; 759 unsigned long flags; 760 unsigned int len; 761 int found = 0; 762 void *buf; 763 764 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 765 766 while ((buf = virtqueue_get_buf(virtscsi_vq->vq, &len)) != NULL) { 767 virtscsi_complete_cmd(vscsi, buf); 768 found++; 769 } 770 771 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 772 773 return found; 774 } 775 776 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 777 { 778 struct virtio_scsi *vscsi = shost_priv(shost); 779 780 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 781 } 782 783 /* 784 * The host guarantees to respond to each command, although I/O 785 * latencies might be higher than on bare metal. Reset the timer 786 * unconditionally to give the host a chance to perform EH. 787 */ 788 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 789 { 790 return SCSI_EH_RESET_TIMER; 791 } 792 793 static const struct scsi_host_template virtscsi_host_template = { 794 .module = THIS_MODULE, 795 .name = "Virtio SCSI HBA", 796 .proc_name = "virtio_scsi", 797 .this_id = -1, 798 .cmd_size = sizeof(struct virtio_scsi_cmd), 799 .queuecommand = virtscsi_queuecommand, 800 .mq_poll = virtscsi_mq_poll, 801 .commit_rqs = virtscsi_commit_rqs, 802 .change_queue_depth = virtscsi_change_queue_depth, 803 .eh_abort_handler = virtscsi_abort, 804 .eh_device_reset_handler = virtscsi_device_reset, 805 .eh_timed_out = virtscsi_eh_timed_out, 806 .slave_alloc = virtscsi_device_alloc, 807 808 .dma_boundary = UINT_MAX, 809 .map_queues = virtscsi_map_queues, 810 .track_queue_depth = 1, 811 }; 812 813 #define virtscsi_config_get(vdev, fld) \ 814 ({ \ 815 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 816 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 817 __val; \ 818 }) 819 820 #define virtscsi_config_set(vdev, fld, val) \ 821 do { \ 822 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 823 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 824 } while(0) 825 826 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 827 struct virtqueue *vq) 828 { 829 spin_lock_init(&virtscsi_vq->vq_lock); 830 virtscsi_vq->vq = vq; 831 } 832 833 static void virtscsi_remove_vqs(struct virtio_device *vdev) 834 { 835 /* Stop all the virtqueues. */ 836 virtio_reset_device(vdev); 837 vdev->config->del_vqs(vdev); 838 } 839 840 static int virtscsi_init(struct virtio_device *vdev, 841 struct virtio_scsi *vscsi) 842 { 843 int err; 844 u32 i; 845 u32 num_vqs, num_poll_vqs, num_req_vqs; 846 vq_callback_t **callbacks; 847 const char **names; 848 struct virtqueue **vqs; 849 struct irq_affinity desc = { .pre_vectors = 2 }; 850 851 num_req_vqs = vscsi->num_queues; 852 num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE; 853 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 854 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 855 GFP_KERNEL); 856 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 857 858 if (!callbacks || !vqs || !names) { 859 err = -ENOMEM; 860 goto out; 861 } 862 863 num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues, 864 num_req_vqs - 1); 865 vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs; 866 vscsi->io_queues[HCTX_TYPE_READ] = 0; 867 vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 868 869 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 870 vscsi->io_queues[HCTX_TYPE_DEFAULT], 871 vscsi->io_queues[HCTX_TYPE_READ], 872 vscsi->io_queues[HCTX_TYPE_POLL]); 873 874 callbacks[0] = virtscsi_ctrl_done; 875 callbacks[1] = virtscsi_event_done; 876 names[0] = "control"; 877 names[1] = "event"; 878 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) { 879 callbacks[i] = virtscsi_req_done; 880 names[i] = "request"; 881 } 882 883 for (; i < num_vqs; i++) { 884 callbacks[i] = NULL; 885 names[i] = "request_poll"; 886 } 887 888 /* Discover virtqueues and write information to configuration. */ 889 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 890 if (err) 891 goto out; 892 893 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 894 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 895 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 896 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 897 vqs[i]); 898 899 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 900 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 901 902 err = 0; 903 904 out: 905 kfree(names); 906 kfree(callbacks); 907 kfree(vqs); 908 if (err) 909 virtscsi_remove_vqs(vdev); 910 return err; 911 } 912 913 static int virtscsi_probe(struct virtio_device *vdev) 914 { 915 struct Scsi_Host *shost; 916 struct virtio_scsi *vscsi; 917 int err; 918 u32 sg_elems, num_targets; 919 u32 cmd_per_lun; 920 u32 num_queues; 921 922 if (!vdev->config->get) { 923 dev_err(&vdev->dev, "%s failure: config access disabled\n", 924 __func__); 925 return -EINVAL; 926 } 927 928 /* We need to know how many queues before we allocate. */ 929 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 930 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 931 932 num_targets = virtscsi_config_get(vdev, max_target) + 1; 933 934 shost = scsi_host_alloc(&virtscsi_host_template, 935 struct_size(vscsi, req_vqs, num_queues)); 936 if (!shost) 937 return -ENOMEM; 938 939 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 940 shost->sg_tablesize = sg_elems; 941 shost->nr_maps = 1; 942 vscsi = shost_priv(shost); 943 vscsi->vdev = vdev; 944 vscsi->num_queues = num_queues; 945 vdev->priv = shost; 946 947 err = virtscsi_init(vdev, vscsi); 948 if (err) 949 goto virtscsi_init_failed; 950 951 if (vscsi->io_queues[HCTX_TYPE_POLL]) 952 shost->nr_maps = HCTX_TYPE_POLL + 1; 953 954 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 955 956 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 957 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 958 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 959 960 /* LUNs > 256 are reported with format 1, so they go in the range 961 * 16640-32767. 962 */ 963 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 964 shost->max_id = num_targets; 965 shost->max_channel = 0; 966 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 967 shost->nr_hw_queues = num_queues; 968 969 #ifdef CONFIG_BLK_DEV_INTEGRITY 970 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 971 int host_prot; 972 973 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 974 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 975 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 976 977 scsi_host_set_prot(shost, host_prot); 978 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 979 } 980 #endif 981 982 err = scsi_add_host(shost, &vdev->dev); 983 if (err) 984 goto scsi_add_host_failed; 985 986 virtio_device_ready(vdev); 987 988 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 989 virtscsi_kick_event_all(vscsi); 990 991 scsi_scan_host(shost); 992 return 0; 993 994 scsi_add_host_failed: 995 vdev->config->del_vqs(vdev); 996 virtscsi_init_failed: 997 scsi_host_put(shost); 998 return err; 999 } 1000 1001 static void virtscsi_remove(struct virtio_device *vdev) 1002 { 1003 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1004 struct virtio_scsi *vscsi = shost_priv(shost); 1005 1006 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1007 virtscsi_cancel_event_work(vscsi); 1008 1009 scsi_remove_host(shost); 1010 virtscsi_remove_vqs(vdev); 1011 scsi_host_put(shost); 1012 } 1013 1014 #ifdef CONFIG_PM_SLEEP 1015 static int virtscsi_freeze(struct virtio_device *vdev) 1016 { 1017 virtscsi_remove_vqs(vdev); 1018 return 0; 1019 } 1020 1021 static int virtscsi_restore(struct virtio_device *vdev) 1022 { 1023 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1024 struct virtio_scsi *vscsi = shost_priv(sh); 1025 int err; 1026 1027 err = virtscsi_init(vdev, vscsi); 1028 if (err) 1029 return err; 1030 1031 virtio_device_ready(vdev); 1032 1033 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1034 virtscsi_kick_event_all(vscsi); 1035 1036 return err; 1037 } 1038 #endif 1039 1040 static struct virtio_device_id id_table[] = { 1041 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1042 { 0 }, 1043 }; 1044 1045 static unsigned int features[] = { 1046 VIRTIO_SCSI_F_HOTPLUG, 1047 VIRTIO_SCSI_F_CHANGE, 1048 #ifdef CONFIG_BLK_DEV_INTEGRITY 1049 VIRTIO_SCSI_F_T10_PI, 1050 #endif 1051 }; 1052 1053 static struct virtio_driver virtio_scsi_driver = { 1054 .feature_table = features, 1055 .feature_table_size = ARRAY_SIZE(features), 1056 .driver.name = KBUILD_MODNAME, 1057 .driver.owner = THIS_MODULE, 1058 .id_table = id_table, 1059 .probe = virtscsi_probe, 1060 #ifdef CONFIG_PM_SLEEP 1061 .freeze = virtscsi_freeze, 1062 .restore = virtscsi_restore, 1063 #endif 1064 .remove = virtscsi_remove, 1065 }; 1066 1067 static int __init virtio_scsi_init(void) 1068 { 1069 int ret = -ENOMEM; 1070 1071 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1072 if (!virtscsi_cmd_cache) { 1073 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1074 goto error; 1075 } 1076 1077 1078 virtscsi_cmd_pool = 1079 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1080 virtscsi_cmd_cache); 1081 if (!virtscsi_cmd_pool) { 1082 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1083 goto error; 1084 } 1085 ret = register_virtio_driver(&virtio_scsi_driver); 1086 if (ret < 0) 1087 goto error; 1088 1089 return 0; 1090 1091 error: 1092 mempool_destroy(virtscsi_cmd_pool); 1093 virtscsi_cmd_pool = NULL; 1094 kmem_cache_destroy(virtscsi_cmd_cache); 1095 virtscsi_cmd_cache = NULL; 1096 return ret; 1097 } 1098 1099 static void __exit virtio_scsi_fini(void) 1100 { 1101 unregister_virtio_driver(&virtio_scsi_driver); 1102 mempool_destroy(virtscsi_cmd_pool); 1103 kmem_cache_destroy(virtscsi_cmd_cache); 1104 } 1105 module_init(virtio_scsi_init); 1106 module_exit(virtio_scsi_fini); 1107 1108 MODULE_DEVICE_TABLE(virtio, id_table); 1109 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1110 MODULE_LICENSE("GPL"); 1111