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_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 void 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; 216 } 217 s->started_vu = false; 218 219 if (!k->set_guest_notifiers) { 220 return; 221 } 222 223 vhost_dev_stop(&s->dev, vdev, true); 224 225 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 226 if (ret < 0) { 227 error_report("vhost guest notifier cleanup failed: %d", ret); 228 return; 229 } 230 231 vhost_dev_disable_notifiers(&s->dev, vdev); 232 } 233 234 static void 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; 243 } 244 245 if (vhost_dev_is_started(&s->dev) == should_start) { 246 return; 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 vhost_user_blk_stop(vdev); 257 } 258 259 } 260 261 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev, 262 uint64_t features, 263 Error **errp) 264 { 265 VHostUserBlk *s = VHOST_USER_BLK(vdev); 266 267 /* Turn on pre-defined features */ 268 virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX); 269 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 270 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 271 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 272 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 273 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 274 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 275 276 if (s->num_queues > 1) { 277 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 278 } 279 280 return vhost_get_features(&s->dev, user_feature_bits, features); 281 } 282 283 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 284 { 285 VHostUserBlk *s = VHOST_USER_BLK(vdev); 286 Error *local_err = NULL; 287 int i, ret; 288 289 if (!vdev->start_on_kick) { 290 return; 291 } 292 293 if (!s->connected) { 294 return; 295 } 296 297 if (vhost_dev_is_started(&s->dev)) { 298 return; 299 } 300 301 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 302 * vhost here instead of waiting for .set_status(). 303 */ 304 ret = vhost_user_blk_start(vdev, &local_err); 305 if (ret < 0) { 306 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 307 qemu_chr_fe_disconnect(&s->chardev); 308 return; 309 } 310 311 /* Kick right away to begin processing requests already in vring */ 312 for (i = 0; i < s->dev.nvqs; i++) { 313 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 314 315 if (!virtio_queue_get_desc_addr(vdev, i)) { 316 continue; 317 } 318 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 319 } 320 } 321 322 static void vhost_user_blk_reset(VirtIODevice *vdev) 323 { 324 VHostUserBlk *s = VHOST_USER_BLK(vdev); 325 326 vhost_dev_free_inflight(s->inflight); 327 } 328 329 static int vhost_user_blk_connect(DeviceState *dev, Error **errp) 330 { 331 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 332 VHostUserBlk *s = VHOST_USER_BLK(vdev); 333 int ret = 0; 334 335 if (s->connected) { 336 return 0; 337 } 338 339 s->dev.num_queues = s->num_queues; 340 s->dev.nvqs = s->num_queues; 341 s->dev.vqs = s->vhost_vqs; 342 s->dev.vq_index = 0; 343 s->dev.backend_features = 0; 344 345 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 346 347 s->vhost_user.supports_config = true; 348 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 349 errp); 350 if (ret < 0) { 351 return ret; 352 } 353 354 s->connected = true; 355 356 /* restore vhost state */ 357 if (virtio_device_started(vdev, vdev->status)) { 358 ret = vhost_user_blk_start(vdev, errp); 359 } 360 361 return ret; 362 } 363 364 static void vhost_user_blk_disconnect(DeviceState *dev) 365 { 366 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 367 VHostUserBlk *s = VHOST_USER_BLK(vdev); 368 369 if (!s->connected) { 370 goto done; 371 } 372 s->connected = false; 373 374 vhost_user_blk_stop(vdev); 375 376 vhost_dev_cleanup(&s->dev); 377 378 done: 379 /* Re-instate the event handler for new connections */ 380 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 381 NULL, dev, NULL, true); 382 } 383 384 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) 385 { 386 DeviceState *dev = opaque; 387 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 388 VHostUserBlk *s = VHOST_USER_BLK(vdev); 389 Error *local_err = NULL; 390 391 switch (event) { 392 case CHR_EVENT_OPENED: 393 if (vhost_user_blk_connect(dev, &local_err) < 0) { 394 error_report_err(local_err); 395 qemu_chr_fe_disconnect(&s->chardev); 396 return; 397 } 398 break; 399 case CHR_EVENT_CLOSED: 400 /* defer close until later to avoid circular close */ 401 vhost_user_async_close(dev, &s->chardev, &s->dev, 402 vhost_user_blk_disconnect); 403 break; 404 case CHR_EVENT_BREAK: 405 case CHR_EVENT_MUX_IN: 406 case CHR_EVENT_MUX_OUT: 407 /* Ignore */ 408 break; 409 } 410 } 411 412 static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) 413 { 414 DeviceState *dev = DEVICE(s); 415 int ret; 416 417 s->connected = false; 418 419 ret = qemu_chr_fe_wait_connected(&s->chardev, errp); 420 if (ret < 0) { 421 return ret; 422 } 423 424 ret = vhost_user_blk_connect(dev, errp); 425 if (ret < 0) { 426 qemu_chr_fe_disconnect(&s->chardev); 427 return ret; 428 } 429 assert(s->connected); 430 431 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 432 VIRTIO_DEVICE(s)->config_len, errp); 433 if (ret < 0) { 434 qemu_chr_fe_disconnect(&s->chardev); 435 vhost_dev_cleanup(&s->dev); 436 return ret; 437 } 438 439 return 0; 440 } 441 442 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 443 { 444 ERRP_GUARD(); 445 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 446 VHostUserBlk *s = VHOST_USER_BLK(vdev); 447 size_t config_size; 448 int retries; 449 int i, ret; 450 451 if (!s->chardev.chr) { 452 error_setg(errp, "chardev is mandatory"); 453 return; 454 } 455 456 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 457 s->num_queues = 1; 458 } 459 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 460 error_setg(errp, "invalid number of IO queues"); 461 return; 462 } 463 464 if (!s->queue_size) { 465 error_setg(errp, "queue size must be non-zero"); 466 return; 467 } 468 if (s->queue_size > VIRTQUEUE_MAX_SIZE) { 469 error_setg(errp, "queue size must not exceed %d", 470 VIRTQUEUE_MAX_SIZE); 471 return; 472 } 473 474 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 475 return; 476 } 477 478 config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, 479 vdev->host_features); 480 virtio_init(vdev, VIRTIO_ID_BLOCK, config_size); 481 482 s->virtqs = g_new(VirtQueue *, s->num_queues); 483 for (i = 0; i < s->num_queues; i++) { 484 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 485 vhost_user_blk_handle_output); 486 } 487 488 s->inflight = g_new0(struct vhost_inflight, 1); 489 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 490 491 retries = VU_REALIZE_CONN_RETRIES; 492 assert(!*errp); 493 do { 494 if (*errp) { 495 error_prepend(errp, "Reconnecting after error: "); 496 error_report_err(*errp); 497 *errp = NULL; 498 } 499 ret = vhost_user_blk_realize_connect(s, errp); 500 } while (ret < 0 && retries--); 501 502 if (ret < 0) { 503 goto virtio_err; 504 } 505 506 /* we're fully initialized, now we can operate, so add the handler */ 507 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, 508 vhost_user_blk_event, NULL, (void *)dev, 509 NULL, true); 510 return; 511 512 virtio_err: 513 g_free(s->vhost_vqs); 514 s->vhost_vqs = NULL; 515 g_free(s->inflight); 516 s->inflight = NULL; 517 for (i = 0; i < s->num_queues; i++) { 518 virtio_delete_queue(s->virtqs[i]); 519 } 520 g_free(s->virtqs); 521 virtio_cleanup(vdev); 522 vhost_user_cleanup(&s->vhost_user); 523 } 524 525 static void vhost_user_blk_device_unrealize(DeviceState *dev) 526 { 527 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 528 VHostUserBlk *s = VHOST_USER_BLK(dev); 529 int i; 530 531 virtio_set_status(vdev, 0); 532 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 533 NULL, NULL, NULL, false); 534 vhost_dev_cleanup(&s->dev); 535 vhost_dev_free_inflight(s->inflight); 536 g_free(s->vhost_vqs); 537 s->vhost_vqs = NULL; 538 g_free(s->inflight); 539 s->inflight = NULL; 540 541 for (i = 0; i < s->num_queues; i++) { 542 virtio_delete_queue(s->virtqs[i]); 543 } 544 g_free(s->virtqs); 545 virtio_cleanup(vdev); 546 vhost_user_cleanup(&s->vhost_user); 547 } 548 549 static void vhost_user_blk_instance_init(Object *obj) 550 { 551 VHostUserBlk *s = VHOST_USER_BLK(obj); 552 553 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 554 "/disk@0,0", DEVICE(obj)); 555 } 556 557 static struct vhost_dev *vhost_user_blk_get_vhost(VirtIODevice *vdev) 558 { 559 VHostUserBlk *s = VHOST_USER_BLK(vdev); 560 return &s->dev; 561 } 562 563 static const VMStateDescription vmstate_vhost_user_blk = { 564 .name = "vhost-user-blk", 565 .minimum_version_id = 1, 566 .version_id = 1, 567 .fields = (const VMStateField[]) { 568 VMSTATE_VIRTIO_DEVICE, 569 VMSTATE_END_OF_LIST() 570 }, 571 }; 572 573 static Property vhost_user_blk_properties[] = { 574 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 575 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 576 VHOST_USER_BLK_AUTO_NUM_QUEUES), 577 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 578 DEFINE_PROP_BIT64("config-wce", VHostUserBlk, parent_obj.host_features, 579 VIRTIO_BLK_F_CONFIG_WCE, true), 580 DEFINE_PROP_BIT64("discard", VHostUserBlk, parent_obj.host_features, 581 VIRTIO_BLK_F_DISCARD, true), 582 DEFINE_PROP_BIT64("write-zeroes", VHostUserBlk, parent_obj.host_features, 583 VIRTIO_BLK_F_WRITE_ZEROES, true), 584 DEFINE_PROP_END_OF_LIST(), 585 }; 586 587 static void vhost_user_blk_class_init(ObjectClass *klass, void *data) 588 { 589 DeviceClass *dc = DEVICE_CLASS(klass); 590 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 591 592 device_class_set_props(dc, vhost_user_blk_properties); 593 dc->vmsd = &vmstate_vhost_user_blk; 594 dc->sync_config = vhost_user_blk_sync_config; 595 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 596 vdc->realize = vhost_user_blk_device_realize; 597 vdc->unrealize = vhost_user_blk_device_unrealize; 598 vdc->get_config = vhost_user_blk_update_config; 599 vdc->set_config = vhost_user_blk_set_config; 600 vdc->get_features = vhost_user_blk_get_features; 601 vdc->set_status = vhost_user_blk_set_status; 602 vdc->reset = vhost_user_blk_reset; 603 vdc->get_vhost = vhost_user_blk_get_vhost; 604 } 605 606 static const TypeInfo vhost_user_blk_info = { 607 .name = TYPE_VHOST_USER_BLK, 608 .parent = TYPE_VIRTIO_DEVICE, 609 .instance_size = sizeof(VHostUserBlk), 610 .instance_init = vhost_user_blk_instance_init, 611 .class_init = vhost_user_blk_class_init, 612 }; 613 614 static void virtio_register_types(void) 615 { 616 type_register_static(&vhost_user_blk_info); 617 } 618 619 type_init(virtio_register_types) 620