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/virtio/vhost.h" 26 #include "hw/virtio/vhost-user-blk.h" 27 #include "hw/virtio/virtio.h" 28 #include "hw/virtio/virtio-bus.h" 29 #include "hw/virtio/virtio-access.h" 30 #include "sysemu/sysemu.h" 31 #include "sysemu/runstate.h" 32 33 static const int user_feature_bits[] = { 34 VIRTIO_BLK_F_SIZE_MAX, 35 VIRTIO_BLK_F_SEG_MAX, 36 VIRTIO_BLK_F_GEOMETRY, 37 VIRTIO_BLK_F_BLK_SIZE, 38 VIRTIO_BLK_F_TOPOLOGY, 39 VIRTIO_BLK_F_MQ, 40 VIRTIO_BLK_F_RO, 41 VIRTIO_BLK_F_FLUSH, 42 VIRTIO_BLK_F_CONFIG_WCE, 43 VIRTIO_BLK_F_DISCARD, 44 VIRTIO_BLK_F_WRITE_ZEROES, 45 VIRTIO_F_VERSION_1, 46 VIRTIO_RING_F_INDIRECT_DESC, 47 VIRTIO_RING_F_EVENT_IDX, 48 VIRTIO_F_NOTIFY_ON_EMPTY, 49 VHOST_INVALID_FEATURE_BIT 50 }; 51 52 static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config) 53 { 54 VHostUserBlk *s = VHOST_USER_BLK(vdev); 55 56 memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config)); 57 } 58 59 static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config) 60 { 61 VHostUserBlk *s = VHOST_USER_BLK(vdev); 62 struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config; 63 int ret; 64 65 if (blkcfg->wce == s->blkcfg.wce) { 66 return; 67 } 68 69 ret = vhost_dev_set_config(&s->dev, &blkcfg->wce, 70 offsetof(struct virtio_blk_config, wce), 71 sizeof(blkcfg->wce), 72 VHOST_SET_CONFIG_TYPE_MASTER); 73 if (ret) { 74 error_report("set device config space failed"); 75 return; 76 } 77 78 s->blkcfg.wce = blkcfg->wce; 79 } 80 81 static int vhost_user_blk_handle_config_change(struct vhost_dev *dev) 82 { 83 int ret; 84 struct virtio_blk_config blkcfg; 85 VHostUserBlk *s = VHOST_USER_BLK(dev->vdev); 86 87 ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg, 88 sizeof(struct virtio_blk_config)); 89 if (ret < 0) { 90 error_report("get config space failed"); 91 return -1; 92 } 93 94 /* valid for resize only */ 95 if (blkcfg.capacity != s->blkcfg.capacity) { 96 s->blkcfg.capacity = blkcfg.capacity; 97 memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config)); 98 virtio_notify_config(dev->vdev); 99 } 100 101 return 0; 102 } 103 104 const VhostDevConfigOps blk_ops = { 105 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change, 106 }; 107 108 static int vhost_user_blk_start(VirtIODevice *vdev) 109 { 110 VHostUserBlk *s = VHOST_USER_BLK(vdev); 111 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 112 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 113 int i, ret; 114 115 if (!k->set_guest_notifiers) { 116 error_report("binding does not support guest notifiers"); 117 return -ENOSYS; 118 } 119 120 ret = vhost_dev_enable_notifiers(&s->dev, vdev); 121 if (ret < 0) { 122 error_report("Error enabling host notifiers: %d", -ret); 123 return ret; 124 } 125 126 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); 127 if (ret < 0) { 128 error_report("Error binding guest notifier: %d", -ret); 129 goto err_host_notifiers; 130 } 131 132 s->dev.acked_features = vdev->guest_features; 133 134 ret = vhost_dev_prepare_inflight(&s->dev, vdev); 135 if (ret < 0) { 136 error_report("Error set inflight format: %d", -ret); 137 goto err_guest_notifiers; 138 } 139 140 if (!s->inflight->addr) { 141 ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight); 142 if (ret < 0) { 143 error_report("Error get inflight: %d", -ret); 144 goto err_guest_notifiers; 145 } 146 } 147 148 ret = vhost_dev_set_inflight(&s->dev, s->inflight); 149 if (ret < 0) { 150 error_report("Error set inflight: %d", -ret); 151 goto err_guest_notifiers; 152 } 153 154 ret = vhost_dev_start(&s->dev, vdev); 155 if (ret < 0) { 156 error_report("Error starting vhost: %d", -ret); 157 goto err_guest_notifiers; 158 } 159 s->started_vu = true; 160 161 /* guest_notifier_mask/pending not used yet, so just unmask 162 * everything here. virtio-pci will do the right thing by 163 * enabling/disabling irqfd. 164 */ 165 for (i = 0; i < s->dev.nvqs; i++) { 166 vhost_virtqueue_mask(&s->dev, vdev, i, false); 167 } 168 169 return ret; 170 171 err_guest_notifiers: 172 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 173 err_host_notifiers: 174 vhost_dev_disable_notifiers(&s->dev, vdev); 175 return ret; 176 } 177 178 static void vhost_user_blk_stop(VirtIODevice *vdev) 179 { 180 VHostUserBlk *s = VHOST_USER_BLK(vdev); 181 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 182 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 183 int ret; 184 185 if (!s->started_vu) { 186 return; 187 } 188 s->started_vu = false; 189 190 if (!k->set_guest_notifiers) { 191 return; 192 } 193 194 vhost_dev_stop(&s->dev, vdev); 195 196 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 197 if (ret < 0) { 198 error_report("vhost guest notifier cleanup failed: %d", ret); 199 return; 200 } 201 202 vhost_dev_disable_notifiers(&s->dev, vdev); 203 } 204 205 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status) 206 { 207 VHostUserBlk *s = VHOST_USER_BLK(vdev); 208 bool should_start = virtio_device_started(vdev, status); 209 int ret; 210 211 if (!vdev->vm_running) { 212 should_start = false; 213 } 214 215 if (!s->connected) { 216 return; 217 } 218 219 if (s->dev.started == should_start) { 220 return; 221 } 222 223 if (should_start) { 224 ret = vhost_user_blk_start(vdev); 225 if (ret < 0) { 226 error_report("vhost-user-blk: vhost start failed: %s", 227 strerror(-ret)); 228 qemu_chr_fe_disconnect(&s->chardev); 229 } 230 } else { 231 vhost_user_blk_stop(vdev); 232 } 233 234 } 235 236 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev, 237 uint64_t features, 238 Error **errp) 239 { 240 VHostUserBlk *s = VHOST_USER_BLK(vdev); 241 242 /* Turn on pre-defined features */ 243 virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX); 244 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 245 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 246 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 247 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 248 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 249 virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD); 250 virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES); 251 252 if (s->config_wce) { 253 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE); 254 } 255 if (s->num_queues > 1) { 256 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 257 } 258 259 return vhost_get_features(&s->dev, user_feature_bits, features); 260 } 261 262 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 263 { 264 VHostUserBlk *s = VHOST_USER_BLK(vdev); 265 int i, ret; 266 267 if (!vdev->start_on_kick) { 268 return; 269 } 270 271 if (!s->connected) { 272 return; 273 } 274 275 if (s->dev.started) { 276 return; 277 } 278 279 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 280 * vhost here instead of waiting for .set_status(). 281 */ 282 ret = vhost_user_blk_start(vdev); 283 if (ret < 0) { 284 error_report("vhost-user-blk: vhost start failed: %s", 285 strerror(-ret)); 286 qemu_chr_fe_disconnect(&s->chardev); 287 return; 288 } 289 290 /* Kick right away to begin processing requests already in vring */ 291 for (i = 0; i < s->dev.nvqs; i++) { 292 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 293 294 if (!virtio_queue_get_desc_addr(vdev, i)) { 295 continue; 296 } 297 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 298 } 299 } 300 301 static void vhost_user_blk_reset(VirtIODevice *vdev) 302 { 303 VHostUserBlk *s = VHOST_USER_BLK(vdev); 304 305 vhost_dev_free_inflight(s->inflight); 306 } 307 308 static int vhost_user_blk_connect(DeviceState *dev) 309 { 310 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 311 VHostUserBlk *s = VHOST_USER_BLK(vdev); 312 int ret = 0; 313 314 if (s->connected) { 315 return 0; 316 } 317 s->connected = true; 318 319 s->dev.nvqs = s->num_queues; 320 s->dev.vqs = s->vhost_vqs; 321 s->dev.vq_index = 0; 322 s->dev.backend_features = 0; 323 324 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 325 326 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0); 327 if (ret < 0) { 328 error_report("vhost-user-blk: vhost initialization failed: %s", 329 strerror(-ret)); 330 return ret; 331 } 332 333 /* restore vhost state */ 334 if (virtio_device_started(vdev, vdev->status)) { 335 ret = vhost_user_blk_start(vdev); 336 if (ret < 0) { 337 error_report("vhost-user-blk: vhost start failed: %s", 338 strerror(-ret)); 339 return ret; 340 } 341 } 342 343 return 0; 344 } 345 346 static void vhost_user_blk_disconnect(DeviceState *dev) 347 { 348 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 349 VHostUserBlk *s = VHOST_USER_BLK(vdev); 350 351 if (!s->connected) { 352 return; 353 } 354 s->connected = false; 355 356 vhost_user_blk_stop(vdev); 357 358 vhost_dev_cleanup(&s->dev); 359 } 360 361 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event); 362 363 static void vhost_user_blk_chr_closed_bh(void *opaque) 364 { 365 DeviceState *dev = opaque; 366 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 367 VHostUserBlk *s = VHOST_USER_BLK(vdev); 368 369 vhost_user_blk_disconnect(dev); 370 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 371 NULL, opaque, 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); 379 380 switch (event) { 381 case CHR_EVENT_OPENED: 382 if (vhost_user_blk_connect(dev) < 0) { 383 qemu_chr_fe_disconnect(&s->chardev); 384 return; 385 } 386 break; 387 case CHR_EVENT_CLOSED: 388 /* 389 * A close event may happen during a read/write, but vhost 390 * code assumes the vhost_dev remains setup, so delay the 391 * stop & clear. There are two possible paths to hit this 392 * disconnect event: 393 * 1. When VM is in the RUN_STATE_PRELAUNCH state. The 394 * vhost_user_blk_device_realize() is a caller. 395 * 2. In tha main loop phase after VM start. 396 * 397 * For p2 the disconnect event will be delayed. We can't 398 * do the same for p1, because we are not running the loop 399 * at this moment. So just skip this step and perform 400 * disconnect in the caller function. 401 * 402 * TODO: maybe it is a good idea to make the same fix 403 * for other vhost-user devices. 404 */ 405 if (runstate_is_running()) { 406 AioContext *ctx = qemu_get_current_aio_context(); 407 408 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL, 409 NULL, NULL, false); 410 aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque); 411 } 412 413 /* 414 * Move vhost device to the stopped state. The vhost-user device 415 * will be clean up and disconnected in BH. This can be useful in 416 * the vhost migration code. If disconnect was caught there is an 417 * option for the general vhost code to get the dev state without 418 * knowing its type (in this case vhost-user). 419 */ 420 s->dev.started = false; 421 break; 422 case CHR_EVENT_BREAK: 423 case CHR_EVENT_MUX_IN: 424 case CHR_EVENT_MUX_OUT: 425 /* Ignore */ 426 break; 427 } 428 } 429 430 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 431 { 432 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 433 VHostUserBlk *s = VHOST_USER_BLK(vdev); 434 Error *err = NULL; 435 int i, ret; 436 437 if (!s->chardev.chr) { 438 error_setg(errp, "vhost-user-blk: chardev is mandatory"); 439 return; 440 } 441 442 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 443 s->num_queues = 1; 444 } 445 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 446 error_setg(errp, "vhost-user-blk: invalid number of IO queues"); 447 return; 448 } 449 450 if (!s->queue_size) { 451 error_setg(errp, "vhost-user-blk: queue size must be non-zero"); 452 return; 453 } 454 455 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 456 return; 457 } 458 459 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, 460 sizeof(struct virtio_blk_config)); 461 462 s->virtqs = g_new(VirtQueue *, s->num_queues); 463 for (i = 0; i < s->num_queues; i++) { 464 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 465 vhost_user_blk_handle_output); 466 } 467 468 s->inflight = g_new0(struct vhost_inflight, 1); 469 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 470 s->connected = false; 471 472 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 473 NULL, (void *)dev, NULL, true); 474 475 reconnect: 476 if (qemu_chr_fe_wait_connected(&s->chardev, &err) < 0) { 477 error_report_err(err); 478 goto virtio_err; 479 } 480 481 /* check whether vhost_user_blk_connect() failed or not */ 482 if (!s->connected) { 483 goto reconnect; 484 } 485 486 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 487 sizeof(struct virtio_blk_config)); 488 if (ret < 0) { 489 error_report("vhost-user-blk: get block config failed"); 490 goto reconnect; 491 } 492 493 if (s->blkcfg.num_queues != s->num_queues) { 494 s->blkcfg.num_queues = s->num_queues; 495 } 496 497 return; 498 499 virtio_err: 500 g_free(s->vhost_vqs); 501 s->vhost_vqs = NULL; 502 g_free(s->inflight); 503 s->inflight = NULL; 504 for (i = 0; i < s->num_queues; i++) { 505 virtio_delete_queue(s->virtqs[i]); 506 } 507 g_free(s->virtqs); 508 virtio_cleanup(vdev); 509 vhost_user_cleanup(&s->vhost_user); 510 } 511 512 static void vhost_user_blk_device_unrealize(DeviceState *dev) 513 { 514 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 515 VHostUserBlk *s = VHOST_USER_BLK(dev); 516 int i; 517 518 virtio_set_status(vdev, 0); 519 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 520 NULL, NULL, NULL, false); 521 vhost_dev_cleanup(&s->dev); 522 vhost_dev_free_inflight(s->inflight); 523 g_free(s->vhost_vqs); 524 s->vhost_vqs = NULL; 525 g_free(s->inflight); 526 s->inflight = NULL; 527 528 for (i = 0; i < s->num_queues; i++) { 529 virtio_delete_queue(s->virtqs[i]); 530 } 531 g_free(s->virtqs); 532 virtio_cleanup(vdev); 533 vhost_user_cleanup(&s->vhost_user); 534 } 535 536 static void vhost_user_blk_instance_init(Object *obj) 537 { 538 VHostUserBlk *s = VHOST_USER_BLK(obj); 539 540 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 541 "/disk@0,0", DEVICE(obj)); 542 } 543 544 static const VMStateDescription vmstate_vhost_user_blk = { 545 .name = "vhost-user-blk", 546 .minimum_version_id = 1, 547 .version_id = 1, 548 .fields = (VMStateField[]) { 549 VMSTATE_VIRTIO_DEVICE, 550 VMSTATE_END_OF_LIST() 551 }, 552 }; 553 554 static Property vhost_user_blk_properties[] = { 555 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 556 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 557 VHOST_USER_BLK_AUTO_NUM_QUEUES), 558 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 559 DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true), 560 DEFINE_PROP_END_OF_LIST(), 561 }; 562 563 static void vhost_user_blk_class_init(ObjectClass *klass, void *data) 564 { 565 DeviceClass *dc = DEVICE_CLASS(klass); 566 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 567 568 device_class_set_props(dc, vhost_user_blk_properties); 569 dc->vmsd = &vmstate_vhost_user_blk; 570 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 571 vdc->realize = vhost_user_blk_device_realize; 572 vdc->unrealize = vhost_user_blk_device_unrealize; 573 vdc->get_config = vhost_user_blk_update_config; 574 vdc->set_config = vhost_user_blk_set_config; 575 vdc->get_features = vhost_user_blk_get_features; 576 vdc->set_status = vhost_user_blk_set_status; 577 vdc->reset = vhost_user_blk_reset; 578 } 579 580 static const TypeInfo vhost_user_blk_info = { 581 .name = TYPE_VHOST_USER_BLK, 582 .parent = TYPE_VIRTIO_DEVICE, 583 .instance_size = sizeof(VHostUserBlk), 584 .instance_init = vhost_user_blk_instance_init, 585 .class_init = vhost_user_blk_class_init, 586 }; 587 588 static void virtio_register_types(void) 589 { 590 type_register_static(&vhost_user_blk_info); 591 } 592 593 type_init(virtio_register_types) 594