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