vhost-user-blk.c (17275B)
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 #define REALIZE_CONNECTION_RETRIES 3 36 37 static const int user_feature_bits[] = { 38 VIRTIO_BLK_F_SIZE_MAX, 39 VIRTIO_BLK_F_SEG_MAX, 40 VIRTIO_BLK_F_GEOMETRY, 41 VIRTIO_BLK_F_BLK_SIZE, 42 VIRTIO_BLK_F_TOPOLOGY, 43 VIRTIO_BLK_F_MQ, 44 VIRTIO_BLK_F_RO, 45 VIRTIO_BLK_F_FLUSH, 46 VIRTIO_BLK_F_CONFIG_WCE, 47 VIRTIO_BLK_F_DISCARD, 48 VIRTIO_BLK_F_WRITE_ZEROES, 49 VIRTIO_F_VERSION_1, 50 VIRTIO_RING_F_INDIRECT_DESC, 51 VIRTIO_RING_F_EVENT_IDX, 52 VIRTIO_F_NOTIFY_ON_EMPTY, 53 VIRTIO_F_RING_PACKED, 54 VIRTIO_F_IOMMU_PLATFORM, 55 VIRTIO_F_RING_RESET, 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_MASTER); 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 struct virtio_blk_config blkcfg; 97 VirtIODevice *vdev = dev->vdev; 98 VHostUserBlk *s = VHOST_USER_BLK(dev->vdev); 99 Error *local_err = NULL; 100 101 if (!dev->started) { 102 return 0; 103 } 104 105 ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg, 106 vdev->config_len, &local_err); 107 if (ret < 0) { 108 error_report_err(local_err); 109 return ret; 110 } 111 112 /* valid for resize only */ 113 if (blkcfg.capacity != s->blkcfg.capacity) { 114 s->blkcfg.capacity = blkcfg.capacity; 115 memcpy(dev->vdev->config, &s->blkcfg, vdev->config_len); 116 virtio_notify_config(dev->vdev); 117 } 118 119 return 0; 120 } 121 122 const VhostDevConfigOps blk_ops = { 123 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change, 124 }; 125 126 static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp) 127 { 128 VHostUserBlk *s = VHOST_USER_BLK(vdev); 129 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 130 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 131 int i, ret; 132 133 if (!k->set_guest_notifiers) { 134 error_setg(errp, "binding does not support guest notifiers"); 135 return -ENOSYS; 136 } 137 138 ret = vhost_dev_enable_notifiers(&s->dev, vdev); 139 if (ret < 0) { 140 error_setg_errno(errp, -ret, "Error enabling host notifiers"); 141 return ret; 142 } 143 144 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); 145 if (ret < 0) { 146 error_setg_errno(errp, -ret, "Error binding guest notifier"); 147 goto err_host_notifiers; 148 } 149 150 s->dev.acked_features = vdev->guest_features; 151 152 ret = vhost_dev_prepare_inflight(&s->dev, vdev); 153 if (ret < 0) { 154 error_setg_errno(errp, -ret, "Error setting inflight format"); 155 goto err_guest_notifiers; 156 } 157 158 if (!s->inflight->addr) { 159 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight); 160 if (ret < 0) { 161 error_setg_errno(errp, -ret, "Error getting inflight"); 162 goto err_guest_notifiers; 163 } 164 } 165 166 ret = vhost_dev_set_inflight(&s->dev, s->inflight); 167 if (ret < 0) { 168 error_setg_errno(errp, -ret, "Error setting inflight"); 169 goto err_guest_notifiers; 170 } 171 172 /* guest_notifier_mask/pending not used yet, so just unmask 173 * everything here. virtio-pci will do the right thing by 174 * enabling/disabling irqfd. 175 */ 176 for (i = 0; i < s->dev.nvqs; i++) { 177 vhost_virtqueue_mask(&s->dev, vdev, i, false); 178 } 179 180 s->dev.vq_index_end = s->dev.nvqs; 181 ret = vhost_dev_start(&s->dev, vdev, true); 182 if (ret < 0) { 183 error_setg_errno(errp, -ret, "Error starting vhost"); 184 goto err_guest_notifiers; 185 } 186 s->started_vu = true; 187 188 return ret; 189 190 err_guest_notifiers: 191 for (i = 0; i < s->dev.nvqs; i++) { 192 vhost_virtqueue_mask(&s->dev, vdev, i, true); 193 } 194 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 195 err_host_notifiers: 196 vhost_dev_disable_notifiers(&s->dev, vdev); 197 return ret; 198 } 199 200 static void vhost_user_blk_stop(VirtIODevice *vdev) 201 { 202 VHostUserBlk *s = VHOST_USER_BLK(vdev); 203 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 204 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 205 int ret; 206 207 if (!s->started_vu) { 208 return; 209 } 210 s->started_vu = false; 211 212 if (!k->set_guest_notifiers) { 213 return; 214 } 215 216 vhost_dev_stop(&s->dev, vdev, true); 217 218 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 219 if (ret < 0) { 220 error_report("vhost guest notifier cleanup failed: %d", ret); 221 return; 222 } 223 224 vhost_dev_disable_notifiers(&s->dev, vdev); 225 } 226 227 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status) 228 { 229 VHostUserBlk *s = VHOST_USER_BLK(vdev); 230 bool should_start = virtio_device_should_start(vdev, status); 231 Error *local_err = NULL; 232 int ret; 233 234 if (!s->connected) { 235 return; 236 } 237 238 if (vhost_dev_is_started(&s->dev) == should_start) { 239 return; 240 } 241 242 if (should_start) { 243 ret = vhost_user_blk_start(vdev, &local_err); 244 if (ret < 0) { 245 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 246 qemu_chr_fe_disconnect(&s->chardev); 247 } 248 } else { 249 vhost_user_blk_stop(vdev); 250 } 251 252 } 253 254 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev, 255 uint64_t features, 256 Error **errp) 257 { 258 VHostUserBlk *s = VHOST_USER_BLK(vdev); 259 260 /* Turn on pre-defined features */ 261 virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX); 262 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 263 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 264 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 265 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 266 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 267 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 268 269 if (s->num_queues > 1) { 270 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 271 } 272 273 return vhost_get_features(&s->dev, user_feature_bits, features); 274 } 275 276 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 277 { 278 VHostUserBlk *s = VHOST_USER_BLK(vdev); 279 Error *local_err = NULL; 280 int i, ret; 281 282 if (!vdev->start_on_kick) { 283 return; 284 } 285 286 if (!s->connected) { 287 return; 288 } 289 290 if (vhost_dev_is_started(&s->dev)) { 291 return; 292 } 293 294 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 295 * vhost here instead of waiting for .set_status(). 296 */ 297 ret = vhost_user_blk_start(vdev, &local_err); 298 if (ret < 0) { 299 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 300 qemu_chr_fe_disconnect(&s->chardev); 301 return; 302 } 303 304 /* Kick right away to begin processing requests already in vring */ 305 for (i = 0; i < s->dev.nvqs; i++) { 306 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 307 308 if (!virtio_queue_get_desc_addr(vdev, i)) { 309 continue; 310 } 311 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 312 } 313 } 314 315 static void vhost_user_blk_reset(VirtIODevice *vdev) 316 { 317 VHostUserBlk *s = VHOST_USER_BLK(vdev); 318 319 vhost_dev_free_inflight(s->inflight); 320 } 321 322 static int vhost_user_blk_connect(DeviceState *dev, Error **errp) 323 { 324 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 325 VHostUserBlk *s = VHOST_USER_BLK(vdev); 326 int ret = 0; 327 328 if (s->connected) { 329 return 0; 330 } 331 s->connected = true; 332 333 s->dev.num_queues = s->num_queues; 334 s->dev.nvqs = s->num_queues; 335 s->dev.vqs = s->vhost_vqs; 336 s->dev.vq_index = 0; 337 s->dev.backend_features = 0; 338 339 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 340 341 s->vhost_user.supports_config = true; 342 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 343 errp); 344 if (ret < 0) { 345 return ret; 346 } 347 348 /* restore vhost state */ 349 if (virtio_device_started(vdev, vdev->status)) { 350 ret = vhost_user_blk_start(vdev, errp); 351 if (ret < 0) { 352 return ret; 353 } 354 } 355 356 return 0; 357 } 358 359 static void vhost_user_blk_disconnect(DeviceState *dev) 360 { 361 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 362 VHostUserBlk *s = VHOST_USER_BLK(vdev); 363 364 if (!s->connected) { 365 return; 366 } 367 s->connected = false; 368 369 vhost_user_blk_stop(vdev); 370 371 vhost_dev_cleanup(&s->dev); 372 373 /* Re-instate the event handler for new connections */ 374 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 375 NULL, dev, NULL, true); 376 } 377 378 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) 379 { 380 DeviceState *dev = opaque; 381 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 382 VHostUserBlk *s = VHOST_USER_BLK(vdev); 383 Error *local_err = NULL; 384 385 switch (event) { 386 case CHR_EVENT_OPENED: 387 if (vhost_user_blk_connect(dev, &local_err) < 0) { 388 error_report_err(local_err); 389 qemu_chr_fe_disconnect(&s->chardev); 390 return; 391 } 392 break; 393 case CHR_EVENT_CLOSED: 394 /* defer close until later to avoid circular close */ 395 vhost_user_async_close(dev, &s->chardev, &s->dev, 396 vhost_user_blk_disconnect); 397 break; 398 case CHR_EVENT_BREAK: 399 case CHR_EVENT_MUX_IN: 400 case CHR_EVENT_MUX_OUT: 401 /* Ignore */ 402 break; 403 } 404 } 405 406 static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) 407 { 408 DeviceState *dev = &s->parent_obj.parent_obj; 409 int ret; 410 411 s->connected = false; 412 413 ret = qemu_chr_fe_wait_connected(&s->chardev, errp); 414 if (ret < 0) { 415 return ret; 416 } 417 418 ret = vhost_user_blk_connect(dev, errp); 419 if (ret < 0) { 420 qemu_chr_fe_disconnect(&s->chardev); 421 return ret; 422 } 423 assert(s->connected); 424 425 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 426 s->parent_obj.config_len, errp); 427 if (ret < 0) { 428 qemu_chr_fe_disconnect(&s->chardev); 429 vhost_dev_cleanup(&s->dev); 430 return ret; 431 } 432 433 return 0; 434 } 435 436 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 437 { 438 ERRP_GUARD(); 439 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 440 VHostUserBlk *s = VHOST_USER_BLK(vdev); 441 size_t config_size; 442 int retries; 443 int i, ret; 444 445 if (!s->chardev.chr) { 446 error_setg(errp, "chardev is mandatory"); 447 return; 448 } 449 450 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 451 s->num_queues = 1; 452 } 453 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 454 error_setg(errp, "invalid number of IO queues"); 455 return; 456 } 457 458 if (!s->queue_size) { 459 error_setg(errp, "queue size must be non-zero"); 460 return; 461 } 462 if (s->queue_size > VIRTQUEUE_MAX_SIZE) { 463 error_setg(errp, "queue size must not exceed %d", 464 VIRTQUEUE_MAX_SIZE); 465 return; 466 } 467 468 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 469 return; 470 } 471 472 config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, 473 vdev->host_features); 474 virtio_init(vdev, VIRTIO_ID_BLOCK, config_size); 475 476 s->virtqs = g_new(VirtQueue *, s->num_queues); 477 for (i = 0; i < s->num_queues; i++) { 478 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 479 vhost_user_blk_handle_output); 480 } 481 482 s->inflight = g_new0(struct vhost_inflight, 1); 483 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 484 485 retries = REALIZE_CONNECTION_RETRIES; 486 assert(!*errp); 487 do { 488 if (*errp) { 489 error_prepend(errp, "Reconnecting after error: "); 490 error_report_err(*errp); 491 *errp = NULL; 492 } 493 ret = vhost_user_blk_realize_connect(s, errp); 494 } while (ret < 0 && retries--); 495 496 if (ret < 0) { 497 goto virtio_err; 498 } 499 500 /* we're fully initialized, now we can operate, so add the handler */ 501 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, 502 vhost_user_blk_event, NULL, (void *)dev, 503 NULL, true); 504 return; 505 506 virtio_err: 507 g_free(s->vhost_vqs); 508 s->vhost_vqs = NULL; 509 g_free(s->inflight); 510 s->inflight = NULL; 511 for (i = 0; i < s->num_queues; i++) { 512 virtio_delete_queue(s->virtqs[i]); 513 } 514 g_free(s->virtqs); 515 virtio_cleanup(vdev); 516 vhost_user_cleanup(&s->vhost_user); 517 } 518 519 static void vhost_user_blk_device_unrealize(DeviceState *dev) 520 { 521 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 522 VHostUserBlk *s = VHOST_USER_BLK(dev); 523 int i; 524 525 virtio_set_status(vdev, 0); 526 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 527 NULL, NULL, NULL, false); 528 vhost_dev_cleanup(&s->dev); 529 vhost_dev_free_inflight(s->inflight); 530 g_free(s->vhost_vqs); 531 s->vhost_vqs = NULL; 532 g_free(s->inflight); 533 s->inflight = NULL; 534 535 for (i = 0; i < s->num_queues; i++) { 536 virtio_delete_queue(s->virtqs[i]); 537 } 538 g_free(s->virtqs); 539 virtio_cleanup(vdev); 540 vhost_user_cleanup(&s->vhost_user); 541 } 542 543 static void vhost_user_blk_instance_init(Object *obj) 544 { 545 VHostUserBlk *s = VHOST_USER_BLK(obj); 546 547 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 548 "/disk@0,0", DEVICE(obj)); 549 } 550 551 static struct vhost_dev *vhost_user_blk_get_vhost(VirtIODevice *vdev) 552 { 553 VHostUserBlk *s = VHOST_USER_BLK(vdev); 554 return &s->dev; 555 } 556 557 static const VMStateDescription vmstate_vhost_user_blk = { 558 .name = "vhost-user-blk", 559 .minimum_version_id = 1, 560 .version_id = 1, 561 .fields = (VMStateField[]) { 562 VMSTATE_VIRTIO_DEVICE, 563 VMSTATE_END_OF_LIST() 564 }, 565 }; 566 567 static Property vhost_user_blk_properties[] = { 568 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 569 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 570 VHOST_USER_BLK_AUTO_NUM_QUEUES), 571 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 572 DEFINE_PROP_BIT64("config-wce", VHostUserBlk, parent_obj.host_features, 573 VIRTIO_BLK_F_CONFIG_WCE, true), 574 DEFINE_PROP_BIT64("discard", VHostUserBlk, parent_obj.host_features, 575 VIRTIO_BLK_F_DISCARD, true), 576 DEFINE_PROP_BIT64("write-zeroes", VHostUserBlk, parent_obj.host_features, 577 VIRTIO_BLK_F_WRITE_ZEROES, true), 578 DEFINE_PROP_END_OF_LIST(), 579 }; 580 581 static void vhost_user_blk_class_init(ObjectClass *klass, void *data) 582 { 583 DeviceClass *dc = DEVICE_CLASS(klass); 584 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 585 586 device_class_set_props(dc, vhost_user_blk_properties); 587 dc->vmsd = &vmstate_vhost_user_blk; 588 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 589 vdc->realize = vhost_user_blk_device_realize; 590 vdc->unrealize = vhost_user_blk_device_unrealize; 591 vdc->get_config = vhost_user_blk_update_config; 592 vdc->set_config = vhost_user_blk_set_config; 593 vdc->get_features = vhost_user_blk_get_features; 594 vdc->set_status = vhost_user_blk_set_status; 595 vdc->reset = vhost_user_blk_reset; 596 vdc->get_vhost = vhost_user_blk_get_vhost; 597 } 598 599 static const TypeInfo vhost_user_blk_info = { 600 .name = TYPE_VHOST_USER_BLK, 601 .parent = TYPE_VIRTIO_DEVICE, 602 .instance_size = sizeof(VHostUserBlk), 603 .instance_init = vhost_user_blk_instance_init, 604 .class_init = vhost_user_blk_class_init, 605 }; 606 607 static void virtio_register_types(void) 608 { 609 type_register_static(&vhost_user_blk_info); 610 } 611 612 type_init(virtio_register_types)