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
 132     if (!s->inflight->addr) {
 133         ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
 134         if (ret < 0) {
 135             error_report("Error get inflight: %d", -ret);
 136             goto err_guest_notifiers;
 137         }
 138     }
 139
 140     ret = vhost_dev_set_inflight(&s->dev, s->inflight);
 141     if (ret < 0) {
 142         error_report("Error set inflight: %d", -ret);
 143         goto err_guest_notifiers;
 144     }
 145
 146     ret = vhost_dev_start(&s->dev, vdev);
 147     if (ret < 0) {
 148         error_report("Error starting vhost: %d", -ret);
 149         goto err_guest_notifiers;
 150     }
 151
 152     /* guest_notifier_mask/pending not used yet, so just unmask
 153      * everything here. virtio-pci will do the right thing by
 154      * enabling/disabling irqfd.
 155      */
 156     for (i = 0; i < s->dev.nvqs; i++) {
 157         vhost_virtqueue_mask(&s->dev, vdev, i, false);
 158     }
 159
 160     return;
 161
 162 err_guest_notifiers:
 163     k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 164 err_host_notifiers:
 165     vhost_dev_disable_notifiers(&s->dev, vdev);
 166 }
 167
 168 static void vhost_user_blk_stop(VirtIODevice *vdev)
 169 {
 170     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 171     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 172     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 173     int ret;
 174
 175     if (!k->set_guest_notifiers) {
 176         return;
 177     }
 178
 179     vhost_dev_stop(&s->dev, vdev);
 180
 181     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 182     if (ret < 0) {
 183         error_report("vhost guest notifier cleanup failed: %d", ret);
 184         return;
 185     }
 186
 187     vhost_dev_disable_notifiers(&s->dev, vdev);
 188 }
 189
 190 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
 191 {
 192     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 193     bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
 194
 195     if (!vdev->vm_running) {
 196         should_start = false;
 197     }
 198
 199     if (s->dev.started == should_start) {
 200         return;
 201     }
 202
 203     if (should_start) {
 204         vhost_user_blk_start(vdev);
 205     } else {
 206         vhost_user_blk_stop(vdev);
 207     }
 208
 209 }
 210
 211 static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
 212                                             uint64_t features,
 213                                             Error **errp)
 214 {
 215     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 216
 217     /* Turn on pre-defined features */
 218     virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
 219     virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
 220     virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
 221     virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
 222     virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
 223     virtio_add_feature(&features, VIRTIO_BLK_F_RO);
 224     virtio_add_feature(&features, VIRTIO_BLK_F_DISCARD);
 225     virtio_add_feature(&features, VIRTIO_BLK_F_WRITE_ZEROES);
 226
 227     if (s->config_wce) {
 228         virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
 229     }
 230     if (s->num_queues > 1) {
 231         virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
 232     }
 233
 234     return vhost_get_features(&s->dev, user_feature_bits, features);
 235 }
 236
 237 static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 238 {
 239     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 240     int i;
 241
 242     if (!(virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1) &&
 243         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1))) {
 244         return;
 245     }
 246
 247     if (s->dev.started) {
 248         return;
 249     }
 250
 251     /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
 252      * vhost here instead of waiting for .set_status().
 253      */
 254     vhost_user_blk_start(vdev);
 255
 256     /* Kick right away to begin processing requests already in vring */
 257     for (i = 0; i < s->dev.nvqs; i++) {
 258         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
 259
 260         if (!virtio_queue_get_desc_addr(vdev, i)) {
 261             continue;
 262         }
 263         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
 264     }
 265 }
 266
 267 static void vhost_user_blk_reset(VirtIODevice *vdev)
 268 {
 269     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 270
 271     vhost_dev_free_inflight(s->inflight);
 272 }
 273
 274 static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 275 {
 276     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 277     VHostUserBlk *s = VHOST_USER_BLK(vdev);
 278     struct vhost_virtqueue *vqs = NULL;
 279     int i, ret;
 280
 281     if (!s->chardev.chr) {
 282         error_setg(errp, "vhost-user-blk: chardev is mandatory");
 283         return;
 284     }
 285
 286     if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
 287         error_setg(errp, "vhost-user-blk: invalid number of IO queues");
 288         return;
 289     }
 290
 291     if (!s->queue_size) {
 292         error_setg(errp, "vhost-user-blk: queue size must be non-zero");
 293         return;
 294     }
 295
 296     if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
 297         return;
 298     }
 299
 300     virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
 301                 sizeof(struct virtio_blk_config));
 302
 303     for (i = 0; i < s->num_queues; i++) {
 304         virtio_add_queue(vdev, s->queue_size,
 305                          vhost_user_blk_handle_output);
 306     }
 307
 308     s->inflight = g_new0(struct vhost_inflight, 1);
 309
 310     s->dev.nvqs = s->num_queues;
 311     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 312     s->dev.vq_index = 0;
 313     s->dev.backend_features = 0;
 314     vqs = s->dev.vqs;
 315
 316     vhost_dev_set_config_notifier(&s->dev, &blk_ops);
 317
 318     ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0);
 319     if (ret < 0) {
 320         error_setg(errp, "vhost-user-blk: vhost initialization failed: %s",
 321                    strerror(-ret));
 322         goto virtio_err;
 323     }
 324
 325     ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg,
 326                               sizeof(struct virtio_blk_config));
 327     if (ret < 0) {
 328         error_setg(errp, "vhost-user-blk: get block config failed");
 329         goto vhost_err;
 330     }
 331
 332     if (s->blkcfg.num_queues != s->num_queues) {
 333         s->blkcfg.num_queues = s->num_queues;
 334     }
 335
 336     return;
 337
 338 vhost_err:
 339     vhost_dev_cleanup(&s->dev);
 340 virtio_err:
 341     g_free(vqs);
 342     g_free(s->inflight);
 343     virtio_cleanup(vdev);
 344     vhost_user_cleanup(&s->vhost_user);
 345 }
 346
 347 static void vhost_user_blk_device_unrealize(DeviceState *dev, Error **errp)
 348 {
 349     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 350     VHostUserBlk *s = VHOST_USER_BLK(dev);
 351     struct vhost_virtqueue *vqs = s->dev.vqs;
 352
 353     vhost_user_blk_set_status(vdev, 0);
 354     vhost_dev_cleanup(&s->dev);
 355     vhost_dev_free_inflight(s->inflight);
 356     g_free(vqs);
 357     g_free(s->inflight);
 358     virtio_cleanup(vdev);
 359     vhost_user_cleanup(&s->vhost_user);
 360 }
 361
 362 static void vhost_user_blk_instance_init(Object *obj)
 363 {
 364     VHostUserBlk *s = VHOST_USER_BLK(obj);
 365
 366     device_add_bootindex_property(obj, &s->bootindex, "bootindex",
 367                                   "/disk@0,0", DEVICE(obj), NULL);
 368 }
 369
 370 static const VMStateDescription vmstate_vhost_user_blk = {
 371     .name = "vhost-user-blk",
 372     .minimum_version_id = 1,
 373     .version_id = 1,
 374     .fields = (VMStateField[]) {
 375         VMSTATE_VIRTIO_DEVICE,
 376         VMSTATE_END_OF_LIST()
 377     },
 378 };
 379
 380 static Property vhost_user_blk_properties[] = {
 381     DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev),
 382     DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1),
 383     DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128),
 384     DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true),
 385     DEFINE_PROP_END_OF_LIST(),
 386 };
 387
 388 static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
 389 {
 390     DeviceClass *dc = DEVICE_CLASS(klass);
 391     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 392
 393     dc->props = vhost_user_blk_properties;
 394     dc->vmsd = &vmstate_vhost_user_blk;
 395     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 396     vdc->realize = vhost_user_blk_device_realize;
 397     vdc->unrealize = vhost_user_blk_device_unrealize;
 398     vdc->get_config = vhost_user_blk_update_config;
 399     vdc->set_config = vhost_user_blk_set_config;
 400     vdc->get_features = vhost_user_blk_get_features;
 401     vdc->set_status = vhost_user_blk_set_status;
 402     vdc->reset = vhost_user_blk_reset;
 403 }
 404
 405 static const TypeInfo vhost_user_blk_info = {
 406     .name = TYPE_VHOST_USER_BLK,
 407     .parent = TYPE_VIRTIO_DEVICE,
 408     .instance_size = sizeof(VHostUserBlk),
 409     .instance_init = vhost_user_blk_instance_init,
 410     .class_init = vhost_user_blk_class_init,
 411 };
 412
 413 static void virtio_register_types(void)
 414 {
 415     type_register_static(&vhost_user_blk_info);
 416 }
 417
 418 type_init(virtio_register_types)