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