1 /* 2 * vhost-user-blk host device 3 * 4 * Copyright(C) 2017 Intel Corporation. 5 * 6 * Authors: 7 * Changpeng Liu <changpeng.liu@intel.com> 8 * 9 * Largely based on the "vhost-user-scsi.c" and "vhost-scsi.c" implemented by: 10 * Felipe Franciosi <felipe@nutanix.com> 11 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 12 * Nicholas Bellinger <nab@risingtidesystems.com> 13 * 14 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 15 * See the COPYING.LIB file in the top-level directory. 16 * 17 */ 18 19 #include "qemu/osdep.h" 20 #include "qapi/error.h" 21 #include "qemu/error-report.h" 22 #include "qemu/cutils.h" 23 #include "hw/qdev-core.h" 24 #include "hw/qdev-properties.h" 25 #include "hw/qdev-properties-system.h" 26 #include "hw/virtio/virtio-blk-common.h" 27 #include "hw/virtio/vhost.h" 28 #include "hw/virtio/vhost-user-blk.h" 29 #include "hw/virtio/virtio.h" 30 #include "hw/virtio/virtio-bus.h" 31 #include "hw/virtio/virtio-access.h" 32 #include "system/system.h" 33 #include "system/runstate.h" 34 35 static const int user_feature_bits[] = { 36 VIRTIO_BLK_F_SIZE_MAX, 37 VIRTIO_BLK_F_SEG_MAX, 38 VIRTIO_BLK_F_GEOMETRY, 39 VIRTIO_BLK_F_BLK_SIZE, 40 VIRTIO_BLK_F_TOPOLOGY, 41 VIRTIO_BLK_F_MQ, 42 VIRTIO_BLK_F_RO, 43 VIRTIO_BLK_F_FLUSH, 44 VIRTIO_BLK_F_CONFIG_WCE, 45 VIRTIO_BLK_F_DISCARD, 46 VIRTIO_BLK_F_WRITE_ZEROES, 47 VIRTIO_F_VERSION_1, 48 VIRTIO_RING_F_INDIRECT_DESC, 49 VIRTIO_RING_F_EVENT_IDX, 50 VIRTIO_F_NOTIFY_ON_EMPTY, 51 VIRTIO_F_RING_PACKED, 52 VIRTIO_F_IOMMU_PLATFORM, 53 VIRTIO_F_RING_RESET, 54 VIRTIO_F_IN_ORDER, 55 VIRTIO_F_NOTIFICATION_DATA, 56 VHOST_INVALID_FEATURE_BIT 57 }; 58 59 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event); 60 61 static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config) 62 { 63 VHostUserBlk *s = VHOST_USER_BLK(vdev); 64 65 /* Our num_queues overrides the device backend */ 66 virtio_stw_p(vdev, &s->blkcfg.num_queues, s->num_queues); 67 68 memcpy(config, &s->blkcfg, vdev->config_len); 69 } 70 71 static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 72 { 73 VHostUserBlk *s = VHOST_USER_BLK(vdev); 74 struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config; 75 int ret; 76 77 if (blkcfg->wce == s->blkcfg.wce) { 78 return; 79 } 80 81 ret = vhost_dev_set_config(&s->dev, &blkcfg->wce, 82 offsetof(struct virtio_blk_config, wce), 83 sizeof(blkcfg->wce), 84 VHOST_SET_CONFIG_TYPE_FRONTEND); 85 if (ret) { 86 error_report("set device config space failed"); 87 return; 88 } 89 90 s->blkcfg.wce = blkcfg->wce; 91 } 92 93 static int vhost_user_blk_sync_config(DeviceState *dev, Error **errp) 94 { 95 int ret; 96 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 97 VHostUserBlk *s = VHOST_USER_BLK(vdev); 98 99 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 100 vdev->config_len, errp); 101 if (ret < 0) { 102 return ret; 103 } 104 105 memcpy(vdev->config, &s->blkcfg, vdev->config_len); 106 virtio_notify_config(vdev); 107 108 return 0; 109 } 110 111 static int vhost_user_blk_handle_config_change(struct vhost_dev *dev) 112 { 113 int ret; 114 Error *local_err = NULL; 115 116 if (!dev->started) { 117 return 0; 118 } 119 120 ret = vhost_user_blk_sync_config(DEVICE(dev->vdev), &local_err); 121 if (ret < 0) { 122 error_report_err(local_err); 123 return ret; 124 } 125 126 return 0; 127 } 128 129 const VhostDevConfigOps blk_ops = { 130 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change, 131 }; 132 133 static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp) 134 { 135 VHostUserBlk *s = VHOST_USER_BLK(vdev); 136 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 137 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 138 int i, ret; 139 140 if (!k->set_guest_notifiers) { 141 error_setg(errp, "binding does not support guest notifiers"); 142 return -ENOSYS; 143 } 144 145 ret = vhost_dev_enable_notifiers(&s->dev, vdev); 146 if (ret < 0) { 147 error_setg_errno(errp, -ret, "Error enabling host notifiers"); 148 return ret; 149 } 150 151 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); 152 if (ret < 0) { 153 error_setg_errno(errp, -ret, "Error binding guest notifier"); 154 goto err_host_notifiers; 155 } 156 157 s->dev.acked_features = vdev->guest_features; 158 159 ret = vhost_dev_prepare_inflight(&s->dev, vdev); 160 if (ret < 0) { 161 error_setg_errno(errp, -ret, "Error setting inflight format"); 162 goto err_guest_notifiers; 163 } 164 165 if (!s->inflight->addr) { 166 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight); 167 if (ret < 0) { 168 error_setg_errno(errp, -ret, "Error getting inflight"); 169 goto err_guest_notifiers; 170 } 171 } 172 173 ret = vhost_dev_set_inflight(&s->dev, s->inflight); 174 if (ret < 0) { 175 error_setg_errno(errp, -ret, "Error setting inflight"); 176 goto err_guest_notifiers; 177 } 178 179 /* guest_notifier_mask/pending not used yet, so just unmask 180 * everything here. virtio-pci will do the right thing by 181 * enabling/disabling irqfd. 182 */ 183 for (i = 0; i < s->dev.nvqs; i++) { 184 vhost_virtqueue_mask(&s->dev, vdev, i, false); 185 } 186 187 s->dev.vq_index_end = s->dev.nvqs; 188 ret = vhost_dev_start(&s->dev, vdev, true); 189 if (ret < 0) { 190 error_setg_errno(errp, -ret, "Error starting vhost"); 191 goto err_guest_notifiers; 192 } 193 s->started_vu = true; 194 195 return ret; 196 197 err_guest_notifiers: 198 for (i = 0; i < s->dev.nvqs; i++) { 199 vhost_virtqueue_mask(&s->dev, vdev, i, true); 200 } 201 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 202 err_host_notifiers: 203 vhost_dev_disable_notifiers(&s->dev, vdev); 204 return ret; 205 } 206 207 static int vhost_user_blk_stop(VirtIODevice *vdev) 208 { 209 VHostUserBlk *s = VHOST_USER_BLK(vdev); 210 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 211 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 212 int ret; 213 214 if (!s->started_vu) { 215 return 0; 216 } 217 s->started_vu = false; 218 219 if (!k->set_guest_notifiers) { 220 return 0; 221 } 222 223 ret = vhost_dev_stop(&s->dev, vdev, true); 224 225 if (k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false) < 0) { 226 error_report("vhost guest notifier cleanup failed: %d", ret); 227 return -1; 228 } 229 230 vhost_dev_disable_notifiers(&s->dev, vdev); 231 return ret; 232 } 233 234 static int vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status) 235 { 236 VHostUserBlk *s = VHOST_USER_BLK(vdev); 237 bool should_start = virtio_device_should_start(vdev, status); 238 Error *local_err = NULL; 239 int ret; 240 241 if (!s->connected) { 242 return -1; 243 } 244 245 if (vhost_dev_is_started(&s->dev) == should_start) { 246 return 0; 247 } 248 249 if (should_start) { 250 ret = vhost_user_blk_start(vdev, &local_err); 251 if (ret < 0) { 252 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 253 qemu_chr_fe_disconnect(&s->chardev); 254 } 255 } else { 256 ret = vhost_user_blk_stop(vdev); 257 if (ret < 0) { 258 return ret; 259 } 260 } 261 return 0; 262 } 263 264 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev, 265 uint64_t features, 266 Error **errp) 267 { 268 VHostUserBlk *s = VHOST_USER_BLK(vdev); 269 270 /* Turn on pre-defined features */ 271 virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX); 272 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 273 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 274 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 275 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 276 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 277 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 278 279 if (s->num_queues > 1) { 280 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 281 } 282 283 return vhost_get_features(&s->dev, user_feature_bits, features); 284 } 285 286 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 287 { 288 VHostUserBlk *s = VHOST_USER_BLK(vdev); 289 Error *local_err = NULL; 290 int i, ret; 291 292 if (!vdev->start_on_kick) { 293 return; 294 } 295 296 if (!s->connected) { 297 return; 298 } 299 300 if (vhost_dev_is_started(&s->dev)) { 301 return; 302 } 303 304 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 305 * vhost here instead of waiting for .set_status(). 306 */ 307 ret = vhost_user_blk_start(vdev, &local_err); 308 if (ret < 0) { 309 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 310 qemu_chr_fe_disconnect(&s->chardev); 311 return; 312 } 313 314 /* Kick right away to begin processing requests already in vring */ 315 for (i = 0; i < s->dev.nvqs; i++) { 316 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 317 318 if (!virtio_queue_get_desc_addr(vdev, i)) { 319 continue; 320 } 321 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 322 } 323 } 324 325 static void vhost_user_blk_reset(VirtIODevice *vdev) 326 { 327 VHostUserBlk *s = VHOST_USER_BLK(vdev); 328 329 vhost_dev_free_inflight(s->inflight); 330 } 331 332 static int vhost_user_blk_connect(DeviceState *dev, Error **errp) 333 { 334 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 335 VHostUserBlk *s = VHOST_USER_BLK(vdev); 336 int ret = 0; 337 338 if (s->connected) { 339 return 0; 340 } 341 342 s->dev.num_queues = s->num_queues; 343 s->dev.nvqs = s->num_queues; 344 s->dev.vqs = s->vhost_vqs; 345 s->dev.vq_index = 0; 346 s->dev.backend_features = 0; 347 348 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 349 350 s->vhost_user.supports_config = true; 351 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 352 errp); 353 if (ret < 0) { 354 return ret; 355 } 356 357 s->connected = true; 358 359 /* restore vhost state */ 360 if (virtio_device_started(vdev, vdev->status)) { 361 ret = vhost_user_blk_start(vdev, errp); 362 } 363 364 return ret; 365 } 366 367 static void vhost_user_blk_disconnect(DeviceState *dev) 368 { 369 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 370 VHostUserBlk *s = VHOST_USER_BLK(vdev); 371 372 if (!s->connected) { 373 goto done; 374 } 375 s->connected = false; 376 377 vhost_user_blk_stop(vdev); 378 379 vhost_dev_cleanup(&s->dev); 380 381 done: 382 /* Re-instate the event handler for new connections */ 383 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 384 NULL, dev, NULL, true); 385 } 386 387 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) 388 { 389 DeviceState *dev = opaque; 390 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 391 VHostUserBlk *s = VHOST_USER_BLK(vdev); 392 Error *local_err = NULL; 393 394 switch (event) { 395 case CHR_EVENT_OPENED: 396 if (vhost_user_blk_connect(dev, &local_err) < 0) { 397 error_report_err(local_err); 398 qemu_chr_fe_disconnect(&s->chardev); 399 return; 400 } 401 break; 402 case CHR_EVENT_CLOSED: 403 /* defer close until later to avoid circular close */ 404 vhost_user_async_close(dev, &s->chardev, &s->dev, 405 vhost_user_blk_disconnect); 406 break; 407 case CHR_EVENT_BREAK: 408 case CHR_EVENT_MUX_IN: 409 case CHR_EVENT_MUX_OUT: 410 /* Ignore */ 411 break; 412 } 413 } 414 415 static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) 416 { 417 DeviceState *dev = DEVICE(s); 418 int ret; 419 420 s->connected = false; 421 422 ret = qemu_chr_fe_wait_connected(&s->chardev, errp); 423 if (ret < 0) { 424 return ret; 425 } 426 427 ret = vhost_user_blk_connect(dev, errp); 428 if (ret < 0) { 429 qemu_chr_fe_disconnect(&s->chardev); 430 return ret; 431 } 432 assert(s->connected); 433 434 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 435 VIRTIO_DEVICE(s)->config_len, errp); 436 if (ret < 0) { 437 qemu_chr_fe_disconnect(&s->chardev); 438 vhost_dev_cleanup(&s->dev); 439 return ret; 440 } 441 442 return 0; 443 } 444 445 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 446 { 447 ERRP_GUARD(); 448 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 449 VHostUserBlk *s = VHOST_USER_BLK(vdev); 450 size_t config_size; 451 int retries; 452 int i, ret; 453 454 if (!s->chardev.chr) { 455 error_setg(errp, "chardev is mandatory"); 456 return; 457 } 458 459 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 460 s->num_queues = 1; 461 } 462 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 463 error_setg(errp, "invalid number of IO queues"); 464 return; 465 } 466 467 if (!s->queue_size) { 468 error_setg(errp, "queue size must be non-zero"); 469 return; 470 } 471 if (s->queue_size > VIRTQUEUE_MAX_SIZE) { 472 error_setg(errp, "queue size must not exceed %d", 473 VIRTQUEUE_MAX_SIZE); 474 return; 475 } 476 477 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 478 return; 479 } 480 481 config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, 482 vdev->host_features); 483 virtio_init(vdev, VIRTIO_ID_BLOCK, config_size); 484 485 s->virtqs = g_new(VirtQueue *, s->num_queues); 486 for (i = 0; i < s->num_queues; i++) { 487 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 488 vhost_user_blk_handle_output); 489 } 490 491 s->inflight = g_new0(struct vhost_inflight, 1); 492 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 493 494 retries = VU_REALIZE_CONN_RETRIES; 495 assert(!*errp); 496 do { 497 if (*errp) { 498 error_prepend(errp, "Reconnecting after error: "); 499 error_report_err(*errp); 500 *errp = NULL; 501 } 502 ret = vhost_user_blk_realize_connect(s, errp); 503 } while (ret < 0 && retries--); 504 505 if (ret < 0) { 506 goto virtio_err; 507 } 508 509 /* we're fully initialized, now we can operate, so add the handler */ 510 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, 511 vhost_user_blk_event, NULL, (void *)dev, 512 NULL, true); 513 return; 514 515 virtio_err: 516 g_free(s->vhost_vqs); 517 s->vhost_vqs = NULL; 518 g_free(s->inflight); 519 s->inflight = NULL; 520 for (i = 0; i < s->num_queues; i++) { 521 virtio_delete_queue(s->virtqs[i]); 522 } 523 g_free(s->virtqs); 524 virtio_cleanup(vdev); 525 vhost_user_cleanup(&s->vhost_user); 526 } 527 528 static void vhost_user_blk_device_unrealize(DeviceState *dev) 529 { 530 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 531 VHostUserBlk *s = VHOST_USER_BLK(dev); 532 int i; 533 534 virtio_set_status(vdev, 0); 535 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 536 NULL, NULL, NULL, false); 537 vhost_dev_cleanup(&s->dev); 538 vhost_dev_free_inflight(s->inflight); 539 g_free(s->vhost_vqs); 540 s->vhost_vqs = NULL; 541 g_free(s->inflight); 542 s->inflight = NULL; 543 544 for (i = 0; i < s->num_queues; i++) { 545 virtio_delete_queue(s->virtqs[i]); 546 } 547 g_free(s->virtqs); 548 virtio_cleanup(vdev); 549 vhost_user_cleanup(&s->vhost_user); 550 } 551 552 static void vhost_user_blk_instance_init(Object *obj) 553 { 554 VHostUserBlk *s = VHOST_USER_BLK(obj); 555 556 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 557 "/disk@0,0", DEVICE(obj)); 558 } 559 560 static struct vhost_dev *vhost_user_blk_get_vhost(VirtIODevice *vdev) 561 { 562 VHostUserBlk *s = VHOST_USER_BLK(vdev); 563 return &s->dev; 564 } 565 566 static const VMStateDescription vmstate_vhost_user_blk = { 567 .name = "vhost-user-blk", 568 .minimum_version_id = 1, 569 .version_id = 1, 570 .fields = (const VMStateField[]) { 571 VMSTATE_VIRTIO_DEVICE, 572 VMSTATE_END_OF_LIST() 573 }, 574 }; 575 576 static const Property vhost_user_blk_properties[] = { 577 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 578 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 579 VHOST_USER_BLK_AUTO_NUM_QUEUES), 580 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 581 DEFINE_PROP_BIT64("config-wce", VHostUserBlk, parent_obj.host_features, 582 VIRTIO_BLK_F_CONFIG_WCE, true), 583 DEFINE_PROP_BIT64("discard", VHostUserBlk, parent_obj.host_features, 584 VIRTIO_BLK_F_DISCARD, true), 585 DEFINE_PROP_BIT64("write-zeroes", VHostUserBlk, parent_obj.host_features, 586 VIRTIO_BLK_F_WRITE_ZEROES, true), 587 }; 588 589 static void vhost_user_blk_class_init(ObjectClass *klass, const void *data) 590 { 591 DeviceClass *dc = DEVICE_CLASS(klass); 592 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 593 594 device_class_set_props(dc, vhost_user_blk_properties); 595 dc->vmsd = &vmstate_vhost_user_blk; 596 dc->sync_config = vhost_user_blk_sync_config; 597 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 598 vdc->realize = vhost_user_blk_device_realize; 599 vdc->unrealize = vhost_user_blk_device_unrealize; 600 vdc->get_config = vhost_user_blk_update_config; 601 vdc->set_config = vhost_user_blk_set_config; 602 vdc->get_features = vhost_user_blk_get_features; 603 vdc->set_status = vhost_user_blk_set_status; 604 vdc->reset = vhost_user_blk_reset; 605 vdc->get_vhost = vhost_user_blk_get_vhost; 606 } 607 608 static const TypeInfo vhost_user_blk_info = { 609 .name = TYPE_VHOST_USER_BLK, 610 .parent = TYPE_VIRTIO_DEVICE, 611 .instance_size = sizeof(VHostUserBlk), 612 .instance_init = vhost_user_blk_instance_init, 613 .class_init = vhost_user_blk_class_init, 614 }; 615 616 static void virtio_register_types(void) 617 { 618 type_register_static(&vhost_user_blk_info); 619 } 620 621 type_init(virtio_register_types) 622