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/vhost.h" 27 #include "hw/virtio/vhost-user-blk.h" 28 #include "hw/virtio/virtio.h" 29 #include "hw/virtio/virtio-bus.h" 30 #include "hw/virtio/virtio-access.h" 31 #include "sysemu/sysemu.h" 32 #include "sysemu/runstate.h" 33 34 #define REALIZE_CONNECTION_RETRIES 3 35 36 static const int user_feature_bits[] = { 37 VIRTIO_BLK_F_SIZE_MAX, 38 VIRTIO_BLK_F_SEG_MAX, 39 VIRTIO_BLK_F_GEOMETRY, 40 VIRTIO_BLK_F_BLK_SIZE, 41 VIRTIO_BLK_F_TOPOLOGY, 42 VIRTIO_BLK_F_MQ, 43 VIRTIO_BLK_F_RO, 44 VIRTIO_BLK_F_FLUSH, 45 VIRTIO_BLK_F_CONFIG_WCE, 46 VIRTIO_BLK_F_DISCARD, 47 VIRTIO_BLK_F_WRITE_ZEROES, 48 VIRTIO_F_VERSION_1, 49 VIRTIO_RING_F_INDIRECT_DESC, 50 VIRTIO_RING_F_EVENT_IDX, 51 VIRTIO_F_NOTIFY_ON_EMPTY, 52 VIRTIO_F_RING_PACKED, 53 VIRTIO_F_IOMMU_PLATFORM, 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, sizeof(struct virtio_blk_config)); 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_MASTER); 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 VHostUserBlk *s = VHOST_USER_BLK(dev->vdev); 96 Error *local_err = NULL; 97 98 ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg, 99 sizeof(struct virtio_blk_config), 100 &local_err); 101 if (ret < 0) { 102 error_report_err(local_err); 103 return ret; 104 } 105 106 /* valid for resize only */ 107 if (blkcfg.capacity != s->blkcfg.capacity) { 108 s->blkcfg.capacity = blkcfg.capacity; 109 memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config)); 110 virtio_notify_config(dev->vdev); 111 } 112 113 return 0; 114 } 115 116 const VhostDevConfigOps blk_ops = { 117 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change, 118 }; 119 120 static int vhost_user_blk_start(VirtIODevice *vdev, Error **errp) 121 { 122 VHostUserBlk *s = VHOST_USER_BLK(vdev); 123 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 124 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 125 int i, ret; 126 127 if (!k->set_guest_notifiers) { 128 error_setg(errp, "binding does not support guest notifiers"); 129 return -ENOSYS; 130 } 131 132 ret = vhost_dev_enable_notifiers(&s->dev, vdev); 133 if (ret < 0) { 134 error_setg_errno(errp, -ret, "Error enabling host notifiers"); 135 return ret; 136 } 137 138 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); 139 if (ret < 0) { 140 error_setg_errno(errp, -ret, "Error binding guest notifier"); 141 goto err_host_notifiers; 142 } 143 144 s->dev.acked_features = vdev->guest_features; 145 146 ret = vhost_dev_prepare_inflight(&s->dev, vdev); 147 if (ret < 0) { 148 error_setg_errno(errp, -ret, "Error setting inflight format"); 149 goto err_guest_notifiers; 150 } 151 152 if (!s->inflight->addr) { 153 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight); 154 if (ret < 0) { 155 error_setg_errno(errp, -ret, "Error getting inflight"); 156 goto err_guest_notifiers; 157 } 158 } 159 160 ret = vhost_dev_set_inflight(&s->dev, s->inflight); 161 if (ret < 0) { 162 error_setg_errno(errp, -ret, "Error setting inflight"); 163 goto err_guest_notifiers; 164 } 165 166 ret = vhost_dev_start(&s->dev, vdev); 167 if (ret < 0) { 168 error_setg_errno(errp, -ret, "Error starting vhost"); 169 goto err_guest_notifiers; 170 } 171 s->started_vu = true; 172 173 /* guest_notifier_mask/pending not used yet, so just unmask 174 * everything here. virtio-pci will do the right thing by 175 * enabling/disabling irqfd. 176 */ 177 for (i = 0; i < s->dev.nvqs; i++) { 178 vhost_virtqueue_mask(&s->dev, vdev, i, false); 179 } 180 181 return ret; 182 183 err_guest_notifiers: 184 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 185 err_host_notifiers: 186 vhost_dev_disable_notifiers(&s->dev, vdev); 187 return ret; 188 } 189 190 static void vhost_user_blk_stop(VirtIODevice *vdev) 191 { 192 VHostUserBlk *s = VHOST_USER_BLK(vdev); 193 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 194 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 195 int ret; 196 197 if (!s->started_vu) { 198 return; 199 } 200 s->started_vu = false; 201 202 if (!k->set_guest_notifiers) { 203 return; 204 } 205 206 vhost_dev_stop(&s->dev, vdev); 207 208 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 209 if (ret < 0) { 210 error_report("vhost guest notifier cleanup failed: %d", ret); 211 return; 212 } 213 214 vhost_dev_disable_notifiers(&s->dev, vdev); 215 } 216 217 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status) 218 { 219 VHostUserBlk *s = VHOST_USER_BLK(vdev); 220 bool should_start = virtio_device_started(vdev, status); 221 Error *local_err = NULL; 222 int ret; 223 224 if (!vdev->vm_running) { 225 should_start = false; 226 } 227 228 if (!s->connected) { 229 return; 230 } 231 232 if (s->dev.started == should_start) { 233 return; 234 } 235 236 if (should_start) { 237 ret = vhost_user_blk_start(vdev, &local_err); 238 if (ret < 0) { 239 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 240 qemu_chr_fe_disconnect(&s->chardev); 241 } 242 } else { 243 vhost_user_blk_stop(vdev); 244 } 245 246 } 247 248 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev, 249 uint64_t features, 250 Error **errp) 251 { 252 VHostUserBlk *s = VHOST_USER_BLK(vdev); 253 254 /* Turn on pre-defined features */ 255 virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX); 256 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 257 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 258 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 259 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 260 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 261 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 262 virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD); 263 virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES); 264 265 if (s->config_wce) { 266 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE); 267 } 268 if (s->num_queues > 1) { 269 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 270 } 271 272 return vhost_get_features(&s->dev, user_feature_bits, features); 273 } 274 275 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 276 { 277 VHostUserBlk *s = VHOST_USER_BLK(vdev); 278 Error *local_err = NULL; 279 int i, ret; 280 281 if (!vdev->start_on_kick) { 282 return; 283 } 284 285 if (!s->connected) { 286 return; 287 } 288 289 if (s->dev.started) { 290 return; 291 } 292 293 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 294 * vhost here instead of waiting for .set_status(). 295 */ 296 ret = vhost_user_blk_start(vdev, &local_err); 297 if (ret < 0) { 298 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 299 qemu_chr_fe_disconnect(&s->chardev); 300 return; 301 } 302 303 /* Kick right away to begin processing requests already in vring */ 304 for (i = 0; i < s->dev.nvqs; i++) { 305 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 306 307 if (!virtio_queue_get_desc_addr(vdev, i)) { 308 continue; 309 } 310 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 311 } 312 } 313 314 static void vhost_user_blk_reset(VirtIODevice *vdev) 315 { 316 VHostUserBlk *s = VHOST_USER_BLK(vdev); 317 318 vhost_dev_free_inflight(s->inflight); 319 } 320 321 static int vhost_user_blk_connect(DeviceState *dev, Error **errp) 322 { 323 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 324 VHostUserBlk *s = VHOST_USER_BLK(vdev); 325 int ret = 0; 326 327 if (s->connected) { 328 return 0; 329 } 330 s->connected = true; 331 332 s->dev.num_queues = s->num_queues; 333 s->dev.nvqs = s->num_queues; 334 s->dev.vqs = s->vhost_vqs; 335 s->dev.vq_index = 0; 336 s->dev.backend_features = 0; 337 338 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 339 340 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 341 errp); 342 if (ret < 0) { 343 return ret; 344 } 345 346 /* restore vhost state */ 347 if (virtio_device_started(vdev, vdev->status)) { 348 ret = vhost_user_blk_start(vdev, errp); 349 if (ret < 0) { 350 return ret; 351 } 352 } 353 354 return 0; 355 } 356 357 static void vhost_user_blk_disconnect(DeviceState *dev) 358 { 359 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 360 VHostUserBlk *s = VHOST_USER_BLK(vdev); 361 362 if (!s->connected) { 363 return; 364 } 365 s->connected = false; 366 367 vhost_user_blk_stop(vdev); 368 369 vhost_dev_cleanup(&s->dev); 370 } 371 372 static void vhost_user_blk_chr_closed_bh(void *opaque) 373 { 374 DeviceState *dev = opaque; 375 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 376 VHostUserBlk *s = VHOST_USER_BLK(vdev); 377 378 vhost_user_blk_disconnect(dev); 379 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 380 NULL, opaque, NULL, true); 381 } 382 383 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) 384 { 385 DeviceState *dev = opaque; 386 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 387 VHostUserBlk *s = VHOST_USER_BLK(vdev); 388 Error *local_err = NULL; 389 390 switch (event) { 391 case CHR_EVENT_OPENED: 392 if (vhost_user_blk_connect(dev, &local_err) < 0) { 393 error_report_err(local_err); 394 qemu_chr_fe_disconnect(&s->chardev); 395 return; 396 } 397 break; 398 case CHR_EVENT_CLOSED: 399 if (!runstate_check(RUN_STATE_SHUTDOWN)) { 400 /* 401 * A close event may happen during a read/write, but vhost 402 * code assumes the vhost_dev remains setup, so delay the 403 * stop & clear. 404 */ 405 AioContext *ctx = qemu_get_current_aio_context(); 406 407 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL, 408 NULL, NULL, false); 409 aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque); 410 411 /* 412 * Move vhost device to the stopped state. The vhost-user device 413 * will be clean up and disconnected in BH. This can be useful in 414 * the vhost migration code. If disconnect was caught there is an 415 * option for the general vhost code to get the dev state without 416 * knowing its type (in this case vhost-user). 417 */ 418 s->dev.started = false; 419 } 420 break; 421 case CHR_EVENT_BREAK: 422 case CHR_EVENT_MUX_IN: 423 case CHR_EVENT_MUX_OUT: 424 /* Ignore */ 425 break; 426 } 427 } 428 429 static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) 430 { 431 DeviceState *dev = &s->parent_obj.parent_obj; 432 int ret; 433 434 s->connected = false; 435 436 ret = qemu_chr_fe_wait_connected(&s->chardev, errp); 437 if (ret < 0) { 438 return ret; 439 } 440 441 ret = vhost_user_blk_connect(dev, errp); 442 if (ret < 0) { 443 qemu_chr_fe_disconnect(&s->chardev); 444 return ret; 445 } 446 assert(s->connected); 447 448 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 449 sizeof(struct virtio_blk_config), errp); 450 if (ret < 0) { 451 qemu_chr_fe_disconnect(&s->chardev); 452 vhost_dev_cleanup(&s->dev); 453 return ret; 454 } 455 456 return 0; 457 } 458 459 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 460 { 461 ERRP_GUARD(); 462 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 463 VHostUserBlk *s = VHOST_USER_BLK(vdev); 464 int retries; 465 int i, ret; 466 467 if (!s->chardev.chr) { 468 error_setg(errp, "chardev is mandatory"); 469 return; 470 } 471 472 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 473 s->num_queues = 1; 474 } 475 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 476 error_setg(errp, "invalid number of IO queues"); 477 return; 478 } 479 480 if (!s->queue_size) { 481 error_setg(errp, "queue size must be non-zero"); 482 return; 483 } 484 if (s->queue_size > VIRTQUEUE_MAX_SIZE) { 485 error_setg(errp, "queue size must not exceed %d", 486 VIRTQUEUE_MAX_SIZE); 487 return; 488 } 489 490 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 491 return; 492 } 493 494 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, 495 sizeof(struct virtio_blk_config)); 496 497 s->virtqs = g_new(VirtQueue *, s->num_queues); 498 for (i = 0; i < s->num_queues; i++) { 499 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 500 vhost_user_blk_handle_output); 501 } 502 503 s->inflight = g_new0(struct vhost_inflight, 1); 504 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 505 506 retries = REALIZE_CONNECTION_RETRIES; 507 assert(!*errp); 508 do { 509 if (*errp) { 510 error_prepend(errp, "Reconnecting after error: "); 511 error_report_err(*errp); 512 *errp = NULL; 513 } 514 ret = vhost_user_blk_realize_connect(s, errp); 515 } while (ret < 0 && retries--); 516 517 if (ret < 0) { 518 goto virtio_err; 519 } 520 521 /* we're fully initialized, now we can operate, so add the handler */ 522 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, 523 vhost_user_blk_event, NULL, (void *)dev, 524 NULL, true); 525 return; 526 527 virtio_err: 528 g_free(s->vhost_vqs); 529 s->vhost_vqs = NULL; 530 g_free(s->inflight); 531 s->inflight = NULL; 532 for (i = 0; i < s->num_queues; i++) { 533 virtio_delete_queue(s->virtqs[i]); 534 } 535 g_free(s->virtqs); 536 virtio_cleanup(vdev); 537 vhost_user_cleanup(&s->vhost_user); 538 } 539 540 static void vhost_user_blk_device_unrealize(DeviceState *dev) 541 { 542 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 543 VHostUserBlk *s = VHOST_USER_BLK(dev); 544 int i; 545 546 virtio_set_status(vdev, 0); 547 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 548 NULL, NULL, NULL, false); 549 vhost_dev_cleanup(&s->dev); 550 vhost_dev_free_inflight(s->inflight); 551 g_free(s->vhost_vqs); 552 s->vhost_vqs = NULL; 553 g_free(s->inflight); 554 s->inflight = NULL; 555 556 for (i = 0; i < s->num_queues; i++) { 557 virtio_delete_queue(s->virtqs[i]); 558 } 559 g_free(s->virtqs); 560 virtio_cleanup(vdev); 561 vhost_user_cleanup(&s->vhost_user); 562 } 563 564 static void vhost_user_blk_instance_init(Object *obj) 565 { 566 VHostUserBlk *s = VHOST_USER_BLK(obj); 567 568 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 569 "/disk@0,0", DEVICE(obj)); 570 } 571 572 static const VMStateDescription vmstate_vhost_user_blk = { 573 .name = "vhost-user-blk", 574 .minimum_version_id = 1, 575 .version_id = 1, 576 .fields = (VMStateField[]) { 577 VMSTATE_VIRTIO_DEVICE, 578 VMSTATE_END_OF_LIST() 579 }, 580 }; 581 582 static Property vhost_user_blk_properties[] = { 583 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 584 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 585 VHOST_USER_BLK_AUTO_NUM_QUEUES), 586 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 587 DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true), 588 DEFINE_PROP_END_OF_LIST(), 589 }; 590 591 static void vhost_user_blk_class_init(ObjectClass *klass, void *data) 592 { 593 DeviceClass *dc = DEVICE_CLASS(klass); 594 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 595 596 device_class_set_props(dc, vhost_user_blk_properties); 597 dc->vmsd = &vmstate_vhost_user_blk; 598 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 599 vdc->realize = vhost_user_blk_device_realize; 600 vdc->unrealize = vhost_user_blk_device_unrealize; 601 vdc->get_config = vhost_user_blk_update_config; 602 vdc->set_config = vhost_user_blk_set_config; 603 vdc->get_features = vhost_user_blk_get_features; 604 vdc->set_status = vhost_user_blk_set_status; 605 vdc->reset = vhost_user_blk_reset; 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