vhost-user-blk.c (17538B)
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 36static 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 57static void vhost_user_blk_event(void *opaque, QEMUChrEvent event); 58 59static 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 69static 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 91static 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 -1; 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 116const VhostDevConfigOps blk_ops = { 117 .vhost_dev_config_notifier = vhost_user_blk_handle_config_change, 118}; 119 120static 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 183err_guest_notifiers: 184 k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 185err_host_notifiers: 186 vhost_dev_disable_notifiers(&s->dev, vdev); 187 return ret; 188} 189 190static 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 217static 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 248static 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_SEG_MAX); 256 virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); 257 virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); 258 virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); 259 virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH); 260 virtio_add_feature(&features, VIRTIO_BLK_F_RO); 261 virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD); 262 virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES); 263 264 if (s->config_wce) { 265 virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE); 266 } 267 if (s->num_queues > 1) { 268 virtio_add_feature(&features, VIRTIO_BLK_F_MQ); 269 } 270 271 return vhost_get_features(&s->dev, user_feature_bits, features); 272} 273 274static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) 275{ 276 VHostUserBlk *s = VHOST_USER_BLK(vdev); 277 Error *local_err = NULL; 278 int i, ret; 279 280 if (!vdev->start_on_kick) { 281 return; 282 } 283 284 if (!s->connected) { 285 return; 286 } 287 288 if (s->dev.started) { 289 return; 290 } 291 292 /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start 293 * vhost here instead of waiting for .set_status(). 294 */ 295 ret = vhost_user_blk_start(vdev, &local_err); 296 if (ret < 0) { 297 error_reportf_err(local_err, "vhost-user-blk: vhost start failed: "); 298 qemu_chr_fe_disconnect(&s->chardev); 299 return; 300 } 301 302 /* Kick right away to begin processing requests already in vring */ 303 for (i = 0; i < s->dev.nvqs; i++) { 304 VirtQueue *kick_vq = virtio_get_queue(vdev, i); 305 306 if (!virtio_queue_get_desc_addr(vdev, i)) { 307 continue; 308 } 309 event_notifier_set(virtio_queue_get_host_notifier(kick_vq)); 310 } 311} 312 313static void vhost_user_blk_reset(VirtIODevice *vdev) 314{ 315 VHostUserBlk *s = VHOST_USER_BLK(vdev); 316 317 vhost_dev_free_inflight(s->inflight); 318} 319 320static int vhost_user_blk_connect(DeviceState *dev, Error **errp) 321{ 322 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 323 VHostUserBlk *s = VHOST_USER_BLK(vdev); 324 int ret = 0; 325 326 if (s->connected) { 327 return 0; 328 } 329 s->connected = true; 330 331 s->dev.num_queues = s->num_queues; 332 s->dev.nvqs = s->num_queues; 333 s->dev.vqs = s->vhost_vqs; 334 s->dev.vq_index = 0; 335 s->dev.backend_features = 0; 336 337 vhost_dev_set_config_notifier(&s->dev, &blk_ops); 338 339 ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 340 errp); 341 if (ret < 0) { 342 return ret; 343 } 344 345 /* restore vhost state */ 346 if (virtio_device_started(vdev, vdev->status)) { 347 ret = vhost_user_blk_start(vdev, errp); 348 if (ret < 0) { 349 return ret; 350 } 351 } 352 353 return 0; 354} 355 356static void vhost_user_blk_disconnect(DeviceState *dev) 357{ 358 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 359 VHostUserBlk *s = VHOST_USER_BLK(vdev); 360 361 if (!s->connected) { 362 return; 363 } 364 s->connected = false; 365 366 vhost_user_blk_stop(vdev); 367 368 vhost_dev_cleanup(&s->dev); 369} 370 371static void vhost_user_blk_chr_closed_bh(void *opaque) 372{ 373 DeviceState *dev = opaque; 374 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 375 VHostUserBlk *s = VHOST_USER_BLK(vdev); 376 377 vhost_user_blk_disconnect(dev); 378 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, 379 NULL, opaque, NULL, true); 380} 381 382static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) 383{ 384 DeviceState *dev = opaque; 385 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 386 VHostUserBlk *s = VHOST_USER_BLK(vdev); 387 Error *local_err = NULL; 388 389 switch (event) { 390 case CHR_EVENT_OPENED: 391 if (vhost_user_blk_connect(dev, &local_err) < 0) { 392 error_report_err(local_err); 393 qemu_chr_fe_disconnect(&s->chardev); 394 return; 395 } 396 break; 397 case CHR_EVENT_CLOSED: 398 if (!runstate_check(RUN_STATE_SHUTDOWN)) { 399 /* 400 * A close event may happen during a read/write, but vhost 401 * code assumes the vhost_dev remains setup, so delay the 402 * stop & clear. 403 */ 404 AioContext *ctx = qemu_get_current_aio_context(); 405 406 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL, 407 NULL, NULL, false); 408 aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque); 409 410 /* 411 * Move vhost device to the stopped state. The vhost-user device 412 * will be clean up and disconnected in BH. This can be useful in 413 * the vhost migration code. If disconnect was caught there is an 414 * option for the general vhost code to get the dev state without 415 * knowing its type (in this case vhost-user). 416 */ 417 s->dev.started = false; 418 } 419 break; 420 case CHR_EVENT_BREAK: 421 case CHR_EVENT_MUX_IN: 422 case CHR_EVENT_MUX_OUT: 423 /* Ignore */ 424 break; 425 } 426} 427 428static int vhost_user_blk_realize_connect(VHostUserBlk *s, Error **errp) 429{ 430 DeviceState *dev = &s->parent_obj.parent_obj; 431 int ret; 432 433 s->connected = false; 434 435 ret = qemu_chr_fe_wait_connected(&s->chardev, errp); 436 if (ret < 0) { 437 return ret; 438 } 439 440 ret = vhost_user_blk_connect(dev, errp); 441 if (ret < 0) { 442 qemu_chr_fe_disconnect(&s->chardev); 443 return ret; 444 } 445 assert(s->connected); 446 447 ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, 448 sizeof(struct virtio_blk_config), errp); 449 if (ret < 0) { 450 qemu_chr_fe_disconnect(&s->chardev); 451 vhost_dev_cleanup(&s->dev); 452 return ret; 453 } 454 455 return 0; 456} 457 458static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) 459{ 460 ERRP_GUARD(); 461 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 462 VHostUserBlk *s = VHOST_USER_BLK(vdev); 463 int retries; 464 int i, ret; 465 466 if (!s->chardev.chr) { 467 error_setg(errp, "chardev is mandatory"); 468 return; 469 } 470 471 if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { 472 s->num_queues = 1; 473 } 474 if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { 475 error_setg(errp, "invalid number of IO queues"); 476 return; 477 } 478 479 if (!s->queue_size) { 480 error_setg(errp, "queue size must be non-zero"); 481 return; 482 } 483 if (s->queue_size > VIRTQUEUE_MAX_SIZE) { 484 error_setg(errp, "queue size must not exceed %d", 485 VIRTQUEUE_MAX_SIZE); 486 return; 487 } 488 489 if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) { 490 return; 491 } 492 493 virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, 494 sizeof(struct virtio_blk_config)); 495 496 s->virtqs = g_new(VirtQueue *, s->num_queues); 497 for (i = 0; i < s->num_queues; i++) { 498 s->virtqs[i] = virtio_add_queue(vdev, s->queue_size, 499 vhost_user_blk_handle_output); 500 } 501 502 s->inflight = g_new0(struct vhost_inflight, 1); 503 s->vhost_vqs = g_new0(struct vhost_virtqueue, s->num_queues); 504 505 retries = REALIZE_CONNECTION_RETRIES; 506 assert(!*errp); 507 do { 508 if (*errp) { 509 error_prepend(errp, "Reconnecting after error: "); 510 error_report_err(*errp); 511 *errp = NULL; 512 } 513 ret = vhost_user_blk_realize_connect(s, errp); 514 } while (ret == -EPROTO && retries--); 515 516 if (ret < 0) { 517 goto virtio_err; 518 } 519 520 /* we're fully initialized, now we can operate, so add the handler */ 521 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, 522 vhost_user_blk_event, NULL, (void *)dev, 523 NULL, true); 524 return; 525 526virtio_err: 527 g_free(s->vhost_vqs); 528 s->vhost_vqs = NULL; 529 g_free(s->inflight); 530 s->inflight = NULL; 531 for (i = 0; i < s->num_queues; i++) { 532 virtio_delete_queue(s->virtqs[i]); 533 } 534 g_free(s->virtqs); 535 virtio_cleanup(vdev); 536 vhost_user_cleanup(&s->vhost_user); 537} 538 539static void vhost_user_blk_device_unrealize(DeviceState *dev) 540{ 541 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 542 VHostUserBlk *s = VHOST_USER_BLK(dev); 543 int i; 544 545 virtio_set_status(vdev, 0); 546 qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, 547 NULL, NULL, NULL, false); 548 vhost_dev_cleanup(&s->dev); 549 vhost_dev_free_inflight(s->inflight); 550 g_free(s->vhost_vqs); 551 s->vhost_vqs = NULL; 552 g_free(s->inflight); 553 s->inflight = NULL; 554 555 for (i = 0; i < s->num_queues; i++) { 556 virtio_delete_queue(s->virtqs[i]); 557 } 558 g_free(s->virtqs); 559 virtio_cleanup(vdev); 560 vhost_user_cleanup(&s->vhost_user); 561} 562 563static void vhost_user_blk_instance_init(Object *obj) 564{ 565 VHostUserBlk *s = VHOST_USER_BLK(obj); 566 567 device_add_bootindex_property(obj, &s->bootindex, "bootindex", 568 "/disk@0,0", DEVICE(obj)); 569} 570 571static const VMStateDescription vmstate_vhost_user_blk = { 572 .name = "vhost-user-blk", 573 .minimum_version_id = 1, 574 .version_id = 1, 575 .fields = (VMStateField[]) { 576 VMSTATE_VIRTIO_DEVICE, 577 VMSTATE_END_OF_LIST() 578 }, 579}; 580 581static Property vhost_user_blk_properties[] = { 582 DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), 583 DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 584 VHOST_USER_BLK_AUTO_NUM_QUEUES), 585 DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), 586 DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true), 587 DEFINE_PROP_END_OF_LIST(), 588}; 589 590static void vhost_user_blk_class_init(ObjectClass *klass, void *data) 591{ 592 DeviceClass *dc = DEVICE_CLASS(klass); 593 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 594 595 device_class_set_props(dc, vhost_user_blk_properties); 596 dc->vmsd = &vmstate_vhost_user_blk; 597 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 598 vdc->realize = vhost_user_blk_device_realize; 599 vdc->unrealize = vhost_user_blk_device_unrealize; 600 vdc->get_config = vhost_user_blk_update_config; 601 vdc->set_config = vhost_user_blk_set_config; 602 vdc->get_features = vhost_user_blk_get_features; 603 vdc->set_status = vhost_user_blk_set_status; 604 vdc->reset = vhost_user_blk_reset; 605} 606 607static const TypeInfo vhost_user_blk_info = { 608 .name = TYPE_VHOST_USER_BLK, 609 .parent = TYPE_VIRTIO_DEVICE, 610 .instance_size = sizeof(VHostUserBlk), 611 .instance_init = vhost_user_blk_instance_init, 612 .class_init = vhost_user_blk_class_init, 613}; 614 615static void virtio_register_types(void) 616{ 617 type_register_static(&vhost_user_blk_info); 618} 619 620type_init(virtio_register_types)