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/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
  31 static const int user_feature_bits[] = {
  32     VIRTIO_BLK_F_SIZE_MAX,
  33     VIRTIO_BLK_F_SEG_MAX,
  34     VIRTIO_BLK_F_GEOMETRY,
  35     VIRTIO_BLK_F_BLK_SIZE,
  36     VIRTIO_BLK_F_TOPOLOGY,
  37     VIRTIO_BLK_F_MQ,
  38     VIRTIO_BLK_F_RO,
  39     VIRTIO_BLK_F_FLUSH,
  40     VIRTIO_BLK_F_CONFIG_WCE,
  41     VIRTIO_BLK_F_DISCARD,
  42     VIRTIO_BLK_F_WRITE_ZEROES,
  43     VIRTIO_F_VERSION_1,
  44     VIRTIO_RING_F_INDIRECT_DESC,
  45     VIRTIO_RING_F_EVENT_IDX,
  46     VIRTIO_F_NOTIFY_ON_EMPTY,
  47     VHOST_INVALID_FEATURE_BIT
  48 };
  49
  50 static void vhost_user_blk_update_config(VirtIODevice *vdev, uint8_t *config)
  51 {
  52     VHostUserBlk *s = VHOST_USER_BLK(vdev);
  53
  54     memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
  55 }
  56
  57 static void vhost_user_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
  58 {
  59     VHostUserBlk *s = VHOST_USER_BLK(vdev);
  60     struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
  61     int ret;
  62
  63     if (blkcfg->wce == s->blkcfg.wce) {
  64         return;
  65     }
  66
  67     ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
  68                                offsetof(struct virtio_blk_config, wce),
  69                                sizeof(blkcfg->wce),
  70                                VHOST_SET_CONFIG_TYPE_MASTER);
  71     if (ret) {
  72         error_report("set device config space failed");
  73         return;
  74     }
  75
  76     s->blkcfg.wce = blkcfg->wce;
  77 }
  78
  79 static int vhost_user_blk_handle_config_change(struct vhost_dev *dev)
  80 {
  81     int ret;
  82     struct virtio_blk_config blkcfg;
  83     VHostUserBlk *s = VHOST_USER_BLK(dev->vdev);
  84
  85     ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
  86                                sizeof(struct virtio_blk_config));
  87     if (ret < 0) {
  88         error_report("get config space failed");
  89         return -1;
  90     }
  91
  92     /* valid for resize only */
  93     if (blkcfg.capacity != s->blkcfg.capacity) {
  94         s->blkcfg.capacity = blkcfg.capacity;
  95         memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct virtio_blk_config));
  96         virtio_notify_config(dev->vdev);
  97     }
  98
  99     return 0;
 100 }
 101
 102 const VhostDevConfigOps blk_ops = {
 103     .vhost_dev_config_notifier = vhost_user_blk_handle_config_change,
 104 };
 105
 106 static void vhost_user_blk_start(VirtIODevice *vdev)
 107 {
 108     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 109     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 110     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 111     int i, ret;
 112
 113     if (!k->set_guest_notifiers) {
 114         error_report("binding does not support guest notifiers");
 115         return;
 116     }
 117
 118     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
 119     if (ret < 0) {
 120         error_report("Error enabling host notifiers: %d", -ret);
 121         return;
 122     }
 123
 124     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 125     if (ret < 0) {
 126         error_report("Error binding guest notifier: %d", -ret);
 127         goto err_host_notifiers;
 128     }
 129
 130     s->dev.acked_features = vdev->guest_features;
 131     ret = vhost_dev_start(&s->dev, vdev);
 132     if (ret < 0) {
 133         error_report("Error starting vhost: %d", -ret);
 134         goto err_guest_notifiers;
 135     }
 136
 137     /* guest_notifier_mask/pending not used yet, so just unmask
 138      * everything here. virtio-pci will do the right thing by
 139      * enabling/disabling irqfd.
 140      */
 141     for (i = 0; i < s->dev.nvqs; i++) {
 142         vhost_virtqueue_mask(&s->dev, vdev, i, false);
 143     }
 144
 145     return;
 146
 147 err_guest_notifiers:
 148     k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 149 err_host_notifiers:
 150     vhost_dev_disable_notifiers(&s->dev, vdev);
 151 }
 152
 153 static void vhost_user_blk_stop(VirtIODevice *vdev)
 154 {
 155     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 156     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 157     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 158     int ret;
 159
 160     if (!k->set_guest_notifiers) {
 161         return;
 162     }
 163
 164     vhost_dev_stop(&s->dev, vdev);
 165
 166     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 167     if (ret < 0) {
 168         error_report("vhost guest notifier cleanup failed: %d", ret);
 169         return;
 170     }
 171
 172     vhost_dev_disable_notifiers(&s->dev, vdev);
 173 }
 174
 175 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
 176 {
 177     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 178     bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
 179
 180     if (!vdev->vm_running) {
 181         should_start = false;
 182     }
 183
 184     if (s->dev.started == should_start) {
 185         return;
 186     }
 187
 188     if (should_start) {
 189         vhost_user_blk_start(vdev);
 190     } else {
 191         vhost_user_blk_stop(vdev);
 192     }
 193
 194 }
 195
 196 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
 197                                             uint64_t features,
 198                                             Error **errp)
 199 {
 200     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 201
 202     /* Turn on pre-defined features */
 203     virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
 204     virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
 205     virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
 206     virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
 207     virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
 208     virtio_add_feature(&features, VIRTIO_BLK_F_RO);
 209     virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
 210     virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
 211
 212     if (s->config_wce) {
 213         virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
 214     }
 215     if (s->num_queues > 1) {
 216         virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
 217     }
 218
 219     return vhost_get_features(&s->dev, user_feature_bits, features);
 220 }
 221
 222 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 223 {
 224     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 225     int i;
 226
 227     if (!(virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
 228         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1))) {
 229         return;
 230     }
 231
 232     if (s->dev.started) {
 233         return;
 234     }
 235
 236     /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
 237      * vhost here instead of waiting for .set_status().
 238      */
 239     vhost_user_blk_start(vdev);
 240
 241     /* Kick right away to begin processing requests already in vring */
 242     for (i = 0; i < s->dev.nvqs; i++) {
 243         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
 244
 245         if (!virtio_queue_get_desc_addr(vdev, i)) {
 246             continue;
 247         }
 248         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
 249     }
 250 }
 251
 252 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 253 {
 254     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 255     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 256     VhostUserState *user;
 257     struct vhost_virtqueue *vqs = NULL;
 258     int i, ret;
 259
 260     if (!s->chardev.chr) {
 261         error_setg(errp, "vhost-user-blk: chardev is mandatory");
 262         return;
 263     }
 264
 265     if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
 266         error_setg(errp, "vhost-user-blk: invalid number of IO queues");
 267         return;
 268     }
 269
 270     if (!s->queue_size) {
 271         error_setg(errp, "vhost-user-blk: queue size must be non-zero");
 272         return;
 273     }
 274
 275     user = vhost_user_init();
 276     if (!user) {
 277         error_setg(errp, "vhost-user-blk: failed to init vhost_user");
 278         return;
 279     }
 280
 281     user->chr = &s->chardev;
 282     s->vhost_user = user;
 283
 284     virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
 285                 sizeof(struct virtio_blk_config));
 286
 287     for (i = 0; i < s->num_queues; i++) {
 288         virtio_add_queue(vdev, s->queue_size,
 289                          vhost_user_blk_handle_output);
 290     }
 291
 292     s->dev.nvqs = s->num_queues;
 293     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 294     s->dev.vq_index = 0;
 295     s->dev.backend_features = 0;
 296     vqs = s->dev.vqs;
 297
 298     vhost_dev_set_config_notifier(&s->dev, &blk_ops);
 299
 300     ret = vhost_dev_init(&s->dev, s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
 301     if (ret < 0) {
 302         error_setg(errp, "vhost-user-blk: vhost initialization failed: %s",
 303                    strerror(-ret));
 304         goto virtio_err;
 305     }
 306
 307     ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
 308                               sizeof(struct virtio_blk_config));
 309     if (ret < 0) {
 310         error_setg(errp, "vhost-user-blk: get block config failed");
 311         goto vhost_err;
 312     }
 313
 314     if (s->blkcfg.num_queues != s->num_queues) {
 315         s->blkcfg.num_queues = s->num_queues;
 316     }
 317
 318     return;
 319
 320 vhost_err:
 321     vhost_dev_cleanup(&s->dev);
 322 virtio_err:
 323     g_free(vqs);
 324     virtio_cleanup(vdev);
 325
 326     vhost_user_cleanup(user);
 327     g_free(user);
 328     s->vhost_user = NULL;
 329 }
 330
 331 static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
 332 {
 333     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 334     VHostUserBlk *s = VHOST_USER_BLK(dev);
 335     struct vhost_virtqueue *vqs = s->dev.vqs;
 336
 337     vhost_user_blk_set_status(vdev, 0);
 338     vhost_dev_cleanup(&s->dev);
 339     g_free(vqs);
 340     virtio_cleanup(vdev);
 341
 342     if (s->vhost_user) {
 343         vhost_user_cleanup(s->vhost_user);
 344         g_free(s->vhost_user);
 345         s->vhost_user = NULL;
 346     }
 347 }
 348
 349 static void vhost_user_blk_instance_init(Object *obj)
 350 {
 351     VHostUserBlk *s = VHOST_USER_BLK(obj);
 352
 353     device_add_bootindex_property(obj, &s->bootindex, "bootindex",
 354                                   "/disk@0,0", DEVICE(obj), NULL);
 355 }
 356
 357 static const VMStateDescription vmstate_vhost_user_blk = {
 358     .name = "vhost-user-blk",
 359     .minimum_version_id = 1,
 360     .version_id = 1,
 361     .fields = (VMStateField[]) {
 362         VMSTATE_VIRTIO_DEVICE,
 363         VMSTATE_END_OF_LIST()
 364     },
 365 };
 366
 367 static Property vhost_user_blk_properties[] = {
 368     DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
 369     DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1),
 370     DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
 371     DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
 372     DEFINE_PROP_END_OF_LIST(),
 373 };
 374
 375 static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
 376 {
 377     DeviceClass *dc = DEVICE_CLASS(klass);
 378     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 379
 380     dc->props = vhost_user_blk_properties;
 381     dc->vmsd = &vmstate_vhost_user_blk;
 382     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 383     vdc->realize = vhost_user_blk_device_realize;
 384     vdc->unrealize = vhost_user_blk_device_unrealize;
 385     vdc->get_config = vhost_user_blk_update_config;
 386     vdc->set_config = vhost_user_blk_set_config;
 387     vdc->get_features = vhost_user_blk_get_features;
 388     vdc->set_status = vhost_user_blk_set_status;
 389 }
 390
 391 static const TypeInfo vhost_user_blk_info = {
 392     .name = TYPE_VHOST_USER_BLK,
 393     .parent = TYPE_VIRTIO_DEVICE,
 394     .instance_size = sizeof(VHostUserBlk),
 395     .instance_init = vhost_user_blk_instance_init,
 396     .class_init = vhost_user_blk_class_init,
 397 };
 398
 399 static void virtio_register_types(void)
 400 {
 401     type_register_static(&vhost_user_blk_info);
 402 }
 403
 404 type_init(virtio_register_types)