hw/block/vhost-user-blk.c

   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 "qom/object.h"
  24 #include "hw/qdev-core.h"
  25 #include "hw/qdev-properties.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 static const int user_feature_bits[] = {
  35     VIRTIO_BLK_F_SIZE_MAX,
  36     VIRTIO_BLK_F_SEG_MAX,
  37     VIRTIO_BLK_F_GEOMETRY,
  38     VIRTIO_BLK_F_BLK_SIZE,
  39     VIRTIO_BLK_F_TOPOLOGY,
  40     VIRTIO_BLK_F_MQ,
  41     VIRTIO_BLK_F_RO,
  42     VIRTIO_BLK_F_FLUSH,
  43     VIRTIO_BLK_F_CONFIG_WCE,
  44     VIRTIO_BLK_F_DISCARD,
  45     VIRTIO_BLK_F_WRITE_ZEROES,
  46     VIRTIO_F_VERSION_1,
  47     VIRTIO_RING_F_INDIRECT_DESC,
  48     VIRTIO_RING_F_EVENT_IDX,
  49     VIRTIO_F_NOTIFY_ON_EMPTY,
  50     VHOST_INVALID_FEATURE_BIT
  51 };
  52
  53 static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
  54 {
  55     VHostUserBlk *s = VHOST_USER_BLK(vdev);
  56
  57     memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
  58 }
  59
  60 static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
  61 {
  62     VHostUserBlk *s = VHOST_USER_BLK(vdev);
  63     struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
  64     int ret;
  65
  66     if (blkcfg->wce == s->blkcfg.wce) {
  67         return;
  68     }
  69
  70     ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
  71                                offsetof(struct virtio_blk_config, wce),
  72                                sizeof(blkcfg->wce),
  73                                VHOST_SET_CONFIG_TYPE_MASTER);
  74     if (ret) {
  75         error_report("set device config space failed");
  76         return;
  77     }
  78
  79     s->blkcfg.wce = blkcfg->wce;
  80 }
  81
  82 static int vhost_user_blk_handle_config_change(struct vhost_dev *dev)
  83 {
  84     int ret;
  85     struct virtio_blk_config blkcfg;
  86     VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
  87
  88     ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
  89                                sizeof(struct virtio_blk_config));
  90     if (ret < 0) {
  91         error_report("get config space failed");
  92         return -1;
  93     }
  94
  95     /* valid for resize only */
  96     if (blkcfg.capacity != s->blkcfg.capacity) {
  97         s->blkcfg.capacity = blkcfg.capacity;
  98         memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config));
  99         virtio_notify_config(dev->vdev);
 100     }
 101
 102     return 0;
 103 }
 104
 105 const VhostDevConfigOps blk_ops = {
 106     .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
 107 };
 108
 109 static int vhost_user_blk_start(VirtIODevice *vdev)
 110 {
 111     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 112     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 113     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 114     int i, ret;
 115
 116     if (!k->set_guest_notifiers) {
 117         error_report("binding does not support guest notifiers");
 118         return -ENOSYS;
 119     }
 120
 121     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
 122     if (ret < 0) {
 123         error_report("Error enabling host notifiers: %d", -ret);
 124         return ret;
 125     }
 126
 127     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 128     if (ret < 0) {
 129         error_report("Error binding guest notifier: %d", -ret);
 130         goto err_host_notifiers;
 131     }
 132
 133     s->dev.acked_features = vdev->guest_features;
 134
 135     if (!s->inflight->addr) {
 136         ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
 137         if (ret < 0) {
 138             error_report("Error get inflight: %d", -ret);
 139             goto err_guest_notifiers;
 140         }
 141     }
 142
 143     ret = vhost_dev_set_inflight(&s->dev, s->inflight);
 144     if (ret < 0) {
 145         error_report("Error set inflight: %d", -ret);
 146         goto err_guest_notifiers;
 147     }
 148
 149     ret = vhost_dev_start(&s->dev, vdev);
 150     if (ret < 0) {
 151         error_report("Error starting vhost: %d", -ret);
 152         goto err_guest_notifiers;
 153     }
 154
 155     /* guest_notifier_mask/pending not used yet, so just unmask
 156      * everything here. virtio-pci will do the right thing by
 157      * enabling/disabling irqfd.
 158      */
 159     for (i = 0; i < s->dev.nvqs; i++) {
 160         vhost_virtqueue_mask(&s->dev, vdev, i, false);
 161     }
 162
 163     return ret;
 164
 165 err_guest_notifiers:
 166     k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 167 err_host_notifiers:
 168     vhost_dev_disable_notifiers(&s->dev, vdev);
 169     return ret;
 170 }
 171
 172 static void vhost_user_blk_stop(VirtIODevice *vdev)
 173 {
 174     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 175     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 176     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 177     int ret;
 178
 179     if (!k->set_guest_notifiers) {
 180         return;
 181     }
 182
 183     vhost_dev_stop(&s->dev, vdev);
 184
 185     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 186     if (ret < 0) {
 187         error_report("vhost guest notifier cleanup failed: %d", ret);
 188         return;
 189     }
 190
 191     vhost_dev_disable_notifiers(&s->dev, vdev);
 192 }
 193
 194 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
 195 {
 196     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 197     bool should_start = virtio_device_started(vdev, status);
 198     int ret;
 199
 200     if (!vdev->vm_running) {
 201         should_start = false;
 202     }
 203
 204     if (!s->connected) {
 205         return;
 206     }
 207
 208     if (s->dev.started == should_start) {
 209         return;
 210     }
 211
 212     if (should_start) {
 213         ret = vhost_user_blk_start(vdev);
 214         if (ret < 0) {
 215             error_report("vhost-user-blk: vhost start failed: %s",
 216                          strerror(-ret));
 217             qemu_chr_fe_disconnect(&s->chardev);
 218         }
 219     } else {
 220         vhost_user_blk_stop(vdev);
 221     }
 222
 223 }
 224
 225 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
 226                                             uint64_t features,
 227                                             Error **errp)
 228 {
 229     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 230
 231     /* Turn on pre-defined features */
 232     virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
 233     virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
 234     virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
 235     virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
 236     virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
 237     virtio_add_feature(&features, VIRTIO_BLK_F_RO);
 238     virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
 239     virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
 240
 241     if (s->config_wce) {
 242         virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
 243     }
 244     if (s->num_queues > 1) {
 245         virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
 246     }
 247
 248     return vhost_get_features(&s->dev, user_feature_bits, features);
 249 }
 250
 251 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 252 {
 253     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 254     int i, ret;
 255
 256     if (!vdev->start_on_kick) {
 257         return;
 258     }
 259
 260     if (!s->connected) {
 261         return;
 262     }
 263
 264     if (s->dev.started) {
 265         return;
 266     }
 267
 268     /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
 269      * vhost here instead of waiting for .set_status().
 270      */
 271     ret = vhost_user_blk_start(vdev);
 272     if (ret < 0) {
 273         error_report("vhost-user-blk: vhost start failed: %s",
 274                      strerror(-ret));
 275         qemu_chr_fe_disconnect(&s->chardev);
 276         return;
 277     }
 278
 279     /* Kick right away to begin processing requests already in vring */
 280     for (i = 0; i < s->dev.nvqs; i++) {
 281         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
 282
 283         if (!virtio_queue_get_desc_addr(vdev, i)) {
 284             continue;
 285         }
 286         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
 287     }
 288 }
 289
 290 static void vhost_user_blk_reset(VirtIODevice *vdev)
 291 {
 292     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 293
 294     vhost_dev_free_inflight(s->inflight);
 295 }
 296
 297 static int vhost_user_blk_connect(DeviceState *dev)
 298 {
 299     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 300     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 301     int ret = 0;
 302
 303     if (s->connected) {
 304         return 0;
 305     }
 306     s->connected = true;
 307
 308     s->dev.nvqs = s->num_queues;
 309     s->dev.vqs = s->vqs;
 310     s->dev.vq_index = 0;
 311     s->dev.backend_features = 0;
 312
 313     vhost_dev_set_config_notifier(&s->dev, &blk_ops);
 314
 315     ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
 316     if (ret < 0) {
 317         error_report("vhost-user-blk: vhost initialization failed: %s",
 318                      strerror(-ret));
 319         return ret;
 320     }
 321
 322     /* restore vhost state */
 323     if (virtio_device_started(vdev, vdev->status)) {
 324         ret = vhost_user_blk_start(vdev);
 325         if (ret < 0) {
 326             error_report("vhost-user-blk: vhost start failed: %s",
 327                          strerror(-ret));
 328             return ret;
 329         }
 330     }
 331
 332     return 0;
 333 }
 334
 335 static void vhost_user_blk_disconnect(DeviceState *dev)
 336 {
 337     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 338     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 339
 340     if (!s->connected) {
 341         return;
 342     }
 343     s->connected = false;
 344
 345     if (s->dev.started) {
 346         vhost_user_blk_stop(vdev);
 347     }
 348
 349     vhost_dev_cleanup(&s->dev);
 350 }
 351
 352 static gboolean vhost_user_blk_watch(GIOChannel *chan, GIOCondition cond,
 353                                      void *opaque)
 354 {
 355     DeviceState *dev = opaque;
 356     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 357     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 358
 359     qemu_chr_fe_disconnect(&s->chardev);
 360
 361     return true;
 362 }
 363
 364 static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
 365 {
 366     DeviceState *dev = opaque;
 367     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 368     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 369
 370     switch (event) {
 371     case CHR_EVENT_OPENED:
 372         if (vhost_user_blk_connect(dev) < 0) {
 373             qemu_chr_fe_disconnect(&s->chardev);
 374             return;
 375         }
 376         s->watch = qemu_chr_fe_add_watch(&s->chardev, G_IO_HUP,
 377                                          vhost_user_blk_watch, dev);
 378         break;
 379     case CHR_EVENT_CLOSED:
 380         vhost_user_blk_disconnect(dev);
 381         if (s->watch) {
 382             g_source_remove(s->watch);
 383             s->watch = 0;
 384         }
 385         break;
 386     case CHR_EVENT_BREAK:
 387     case CHR_EVENT_MUX_IN:
 388     case CHR_EVENT_MUX_OUT:
 389         /* Ignore */
 390         break;
 391     }
 392 }
 393
 394 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 395 {
 396     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 397     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 398     Error *err = NULL;
 399     int i, ret;
 400
 401     if (!s->chardev.chr) {
 402         error_setg(errp, "vhost-user-blk: chardev is mandatory");
 403         return;
 404     }
 405
 406     if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
 407         error_setg(errp, "vhost-user-blk: invalid number of IO queues");
 408         return;
 409     }
 410
 411     if (!s->queue_size) {
 412         error_setg(errp, "vhost-user-blk: queue size must be non-zero");
 413         return;
 414     }
 415
 416     if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
 417         return;
 418     }
 419
 420     virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
 421                 sizeof(struct virtio_blk_config));
 422
 423     for (i = 0; i < s->num_queues; i++) {
 424         virtio_add_queue(vdev, s->queue_size,
 425                          vhost_user_blk_handle_output);
 426     }
 427
 428     s->inflight = g_new0(struct vhost_inflight, 1);
 429     s->vqs = g_new0(struct vhost_virtqueue, s->num_queues);
 430     s->watch = 0;
 431     s->connected = false;
 432
 433     qemu_chr_fe_set_handlers(&s->chardev,  NULL, NULL, vhost_user_blk_event,
 434                              NULL, (void *)dev, NULL, true);
 435
 436 reconnect:
 437     if (qemu_chr_fe_wait_connected(&s->chardev, &err) < 0) {
 438         error_report_err(err);
 439         goto virtio_err;
 440     }
 441
 442     /* check whether vhost_user_blk_connect() failed or not */
 443     if (!s->connected) {
 444         goto reconnect;
 445     }
 446
 447     ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
 448                                sizeof(struct virtio_blk_config));
 449     if (ret < 0) {
 450         error_report("vhost-user-blk: get block config failed");
 451         goto reconnect;
 452     }
 453
 454     if (s->blkcfg.num_queues != s->num_queues) {
 455         s->blkcfg.num_queues = s->num_queues;
 456     }
 457
 458     return;
 459
 460 virtio_err:
 461     g_free(s->vqs);
 462     g_free(s->inflight);
 463     virtio_cleanup(vdev);
 464     vhost_user_cleanup(&s->vhost_user);
 465 }
 466
 467 static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
 468 {
 469     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 470     VHostUserBlk *s = VHOST_USER_BLK(dev);
 471
 472     virtio_set_status(vdev, 0);
 473     qemu_chr_fe_set_handlers(&s->chardev,  NULL, NULL, NULL,
 474                              NULL, NULL, NULL, false);
 475     vhost_dev_cleanup(&s->dev);
 476     vhost_dev_free_inflight(s->inflight);
 477     g_free(s->vqs);
 478     g_free(s->inflight);
 479     virtio_cleanup(vdev);
 480     vhost_user_cleanup(&s->vhost_user);
 481 }
 482
 483 static void vhost_user_blk_instance_init(Object *obj)
 484 {
 485     VHostUserBlk *s = VHOST_USER_BLK(obj);
 486
 487     device_add_bootindex_property(obj, &s->bootindex, "bootindex",
 488                                   "/disk@0,0", DEVICE(obj), NULL);
 489 }
 490
 491 static const VMStateDescription vmstate_vhost_user_blk = {
 492     .name = "vhost-user-blk",
 493     .minimum_version_id = 1,
 494     .version_id = 1,
 495     .fields = (VMStateField[]) {
 496         VMSTATE_VIRTIO_DEVICE,
 497         VMSTATE_END_OF_LIST()
 498     },
 499 };
 500
 501 static Property vhost_user_blk_properties[] = {
 502     DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
 503     DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1),
 504     DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
 505     DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
 506     DEFINE_PROP_END_OF_LIST(),
 507 };
 508
 509 static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
 510 {
 511     DeviceClass *dc = DEVICE_CLASS(klass);
 512     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 513
 514     dc->props = vhost_user_blk_properties;
 515     dc->vmsd = &vmstate_vhost_user_blk;
 516     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 517     vdc->realize = vhost_user_blk_device_realize;
 518     vdc->unrealize = vhost_user_blk_device_unrealize;
 519     vdc->get_config = vhost_user_blk_update_config;
 520     vdc->set_config = vhost_user_blk_set_config;
 521     vdc->get_features = vhost_user_blk_get_features;
 522     vdc->set_status = vhost_user_blk_set_status;
 523     vdc->reset = vhost_user_blk_reset;
 524 }
 525
 526 static const TypeInfo vhost_user_blk_info = {
 527     .name = TYPE_VHOST_USER_BLK,
 528     .parent = TYPE_VIRTIO_DEVICE,
 529     .instance_size = sizeof(VHostUserBlk),
 530     .instance_init = vhost_user_blk_instance_init,
 531     .class_init = vhost_user_blk_class_init,
 532 };
 533
 534 static void virtio_register_types(void)
 535 {
 536     type_register_static(&vhost_user_blk_info);
 537 }
 538
 539 type_init(virtio_register_types)