hw/scsi/vhost-user-scsi.c

   1 /*
   2  * vhost-user-scsi host device
   3  *
   4  * Copyright (c) 2016 Nutanix Inc. All rights reserved.
   5  *
   6  * Author:
   7  *  Felipe Franciosi <felipe@nutanix.com>
   8  *
   9  * This work is largely based on the "vhost-scsi" implementation by:
  10  *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
  11  *  Nicholas Bellinger <nab@risingtidesystems.com>
  12  *
  13  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  14  * See the COPYING.LIB file in the top-level directory.
  15  *
  16  */
  17
  18 #include "qemu/osdep.h"
  19 #include "qapi/error.h"
  20 #include "qemu/error-report.h"
  21 #include "hw/fw-path-provider.h"
  22 #include "hw/qdev-core.h"
  23 #include "hw/qdev-properties.h"
  24 #include "hw/qdev-properties-system.h"
  25 #include "hw/virtio/vhost.h"
  26 #include "hw/virtio/vhost-backend.h"
  27 #include "hw/virtio/vhost-user-scsi.h"
  28 #include "hw/virtio/virtio.h"
  29 #include "chardev/char-fe.h"
  30 #include "sysemu/sysemu.h"
  31
  32 /* Features supported by the host application */
  33 static const int user_feature_bits[] = {
  34     VIRTIO_F_NOTIFY_ON_EMPTY,
  35     VIRTIO_RING_F_INDIRECT_DESC,
  36     VIRTIO_RING_F_EVENT_IDX,
  37     VIRTIO_SCSI_F_HOTPLUG,
  38     VIRTIO_F_RING_RESET,
  39     VIRTIO_F_IN_ORDER,
  40     VIRTIO_F_NOTIFICATION_DATA,
  41     VHOST_INVALID_FEATURE_BIT
  42 };
  43
  44 static int vhost_user_scsi_start(VHostUserSCSI *s, Error **errp)
  45 {
  46     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  47     int ret;
  48
  49     ret = vhost_scsi_common_start(vsc, errp);
  50     s->started_vu = !(ret < 0);
  51
  52     return ret;
  53 }
  54
  55 static void vhost_user_scsi_stop(VHostUserSCSI *s)
  56 {
  57     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  58
  59     if (!s->started_vu) {
  60         return;
  61     }
  62     s->started_vu = false;
  63
  64     vhost_scsi_common_stop(vsc);
  65 }
  66
  67 static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
  68 {
  69     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
  70     DeviceState *dev = DEVICE(vdev);
  71     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  72     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
  73     bool should_start = virtio_device_should_start(vdev, status);
  74     Error *local_err = NULL;
  75     int ret;
  76
  77     if (!s->connected) {
  78         return;
  79     }
  80
  81     if (vhost_dev_is_started(&vsc->dev) == should_start) {
  82         return;
  83     }
  84
  85     if (should_start) {
  86         ret = vhost_user_scsi_start(s, &local_err);
  87         if (ret < 0) {
  88             error_reportf_err(local_err,
  89                               "unable to start vhost-user-scsi: %s: ",
  90                               strerror(-ret));
  91             qemu_chr_fe_disconnect(&vs->conf.chardev);
  92         }
  93     } else {
  94         vhost_user_scsi_stop(s);
  95     }
  96 }
  97
  98 static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
  99 {
 100     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
 101     DeviceState *dev = DEVICE(vdev);
 102     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 103     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 104
 105     Error *local_err = NULL;
 106     int i, ret;
 107
 108     if (!vdev->start_on_kick) {
 109         return;
 110     }
 111
 112     if (!s->connected) {
 113         return;
 114     }
 115
 116     if (vhost_dev_is_started(&vsc->dev)) {
 117         return;
 118     }
 119
 120     /*
 121      * Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
 122      * vhost here instead of waiting for .set_status().
 123      */
 124     ret = vhost_user_scsi_start(s, &local_err);
 125     if (ret < 0) {
 126         error_reportf_err(local_err, "vhost-user-scsi: vhost start failed: ");
 127         qemu_chr_fe_disconnect(&vs->conf.chardev);
 128         return;
 129     }
 130
 131     /* Kick right away to begin processing requests already in vring */
 132     for (i = 0; i < vsc->dev.nvqs; i++) {
 133         VirtQueue *kick_vq = virtio_get_queue(vdev, i);
 134
 135         if (!virtio_queue_get_desc_addr(vdev, i)) {
 136             continue;
 137         }
 138         event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
 139     }
 140 }
 141
 142 static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
 143 {
 144     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 145     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
 146     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 147     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 148     int ret = 0;
 149
 150     if (s->connected) {
 151         return 0;
 152     }
 153
 154     vsc->dev.num_queues = vs->conf.num_queues;
 155     vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 156     vsc->dev.vqs = s->vhost_vqs;
 157     vsc->dev.vq_index = 0;
 158     vsc->dev.backend_features = 0;
 159
 160     ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
 161                          errp);
 162     if (ret < 0) {
 163         return ret;
 164     }
 165
 166     s->connected = true;
 167
 168     /* restore vhost state */
 169     if (virtio_device_started(vdev, vdev->status)) {
 170         ret = vhost_user_scsi_start(s, errp);
 171     }
 172
 173     return ret;
 174 }
 175
 176 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event);
 177
 178 static void vhost_user_scsi_disconnect(DeviceState *dev)
 179 {
 180     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 181     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
 182     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 183     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 184
 185     if (!s->connected) {
 186         goto done;
 187     }
 188     s->connected = false;
 189
 190     vhost_user_scsi_stop(s);
 191
 192     vhost_dev_cleanup(&vsc->dev);
 193
 194 done:
 195     /* Re-instate the event handler for new connections */
 196     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
 197                              vhost_user_scsi_event, NULL, dev, NULL, true);
 198 }
 199
 200 static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
 201 {
 202     DeviceState *dev = opaque;
 203     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 204     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
 205     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 206     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 207     Error *local_err = NULL;
 208
 209     switch (event) {
 210     case CHR_EVENT_OPENED:
 211         if (vhost_user_scsi_connect(dev, &local_err) < 0) {
 212             error_report_err(local_err);
 213             qemu_chr_fe_disconnect(&vs->conf.chardev);
 214             return;
 215         }
 216         break;
 217     case CHR_EVENT_CLOSED:
 218         /* defer close until later to avoid circular close */
 219         vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
 220                                vhost_user_scsi_disconnect);
 221         break;
 222     case CHR_EVENT_BREAK:
 223     case CHR_EVENT_MUX_IN:
 224     case CHR_EVENT_MUX_OUT:
 225         /* Ignore */
 226         break;
 227     }
 228 }
 229
 230 static int vhost_user_scsi_realize_connect(VHostUserSCSI *s, Error **errp)
 231 {
 232     DeviceState *dev = DEVICE(s);
 233     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 234     int ret;
 235
 236     s->connected = false;
 237
 238     ret = qemu_chr_fe_wait_connected(&vs->conf.chardev, errp);
 239     if (ret < 0) {
 240         return ret;
 241     }
 242
 243     ret = vhost_user_scsi_connect(dev, errp);
 244     if (ret < 0) {
 245         qemu_chr_fe_disconnect(&vs->conf.chardev);
 246         return ret;
 247     }
 248     assert(s->connected);
 249
 250     return 0;
 251 }
 252
 253 static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
 254 {
 255     ERRP_GUARD();
 256     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 257     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
 258     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 259     Error *err = NULL;
 260     int ret;
 261     int retries = VU_REALIZE_CONN_RETRIES;
 262
 263     if (!vs->conf.chardev.chr) {
 264         error_setg(errp, "vhost-user-scsi: missing chardev");
 265         return;
 266     }
 267
 268     virtio_scsi_common_realize(dev, vhost_user_scsi_handle_output,
 269                                vhost_user_scsi_handle_output,
 270                                vhost_user_scsi_handle_output, &err);
 271     if (err != NULL) {
 272         error_propagate(errp, err);
 273         return;
 274     }
 275
 276     if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
 277         goto free_virtio;
 278     }
 279
 280     vsc->inflight = g_new0(struct vhost_inflight, 1);
 281     s->vhost_vqs = g_new0(struct vhost_virtqueue,
 282                           VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues);
 283
 284     assert(!*errp);
 285     do {
 286         if (*errp) {
 287             error_prepend(errp, "Reconnecting after error: ");
 288             error_report_err(*errp);
 289             *errp = NULL;
 290         }
 291         ret = vhost_user_scsi_realize_connect(s, errp);
 292     } while (ret < 0 && retries--);
 293
 294     if (ret < 0) {
 295         goto free_vhost;
 296     }
 297
 298     /* we're fully initialized, now we can operate, so add the handler */
 299     qemu_chr_fe_set_handlers(&vs->conf.chardev,  NULL, NULL,
 300                              vhost_user_scsi_event, NULL, (void *)dev,
 301                              NULL, true);
 302     /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
 303     vsc->channel = 0;
 304     vsc->lun = 0;
 305     vsc->target = vs->conf.boot_tpgt;
 306
 307     return;
 308
 309 free_vhost:
 310     g_free(s->vhost_vqs);
 311     s->vhost_vqs = NULL;
 312     g_free(vsc->inflight);
 313     vsc->inflight = NULL;
 314     vhost_user_cleanup(&s->vhost_user);
 315
 316 free_virtio:
 317     virtio_scsi_common_unrealize(dev);
 318 }
 319
 320 static void vhost_user_scsi_unrealize(DeviceState *dev)
 321 {
 322     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 323     VHostUserSCSI *s = VHOST_USER_SCSI(dev);
 324     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 325     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 326
 327     /* This will stop the vhost backend. */
 328     vhost_user_scsi_set_status(vdev, 0);
 329     qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, NULL, NULL, NULL,
 330                              NULL, false);
 331
 332     vhost_dev_cleanup(&vsc->dev);
 333     g_free(s->vhost_vqs);
 334     s->vhost_vqs = NULL;
 335
 336     vhost_dev_free_inflight(vsc->inflight);
 337     g_free(vsc->inflight);
 338     vsc->inflight = NULL;
 339
 340     vhost_user_cleanup(&s->vhost_user);
 341     virtio_scsi_common_unrealize(dev);
 342 }
 343
 344 static Property vhost_user_scsi_properties[] = {
 345     DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
 346     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
 347     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
 348                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
 349     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
 350                        128),
 351     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 352                        0xFFFF),
 353     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 354     DEFINE_PROP_BIT64("hotplug", VHostSCSICommon, host_features,
 355                                                   VIRTIO_SCSI_F_HOTPLUG,
 356                                                   true),
 357     DEFINE_PROP_BIT64("param_change", VHostSCSICommon, host_features,
 358                                                        VIRTIO_SCSI_F_CHANGE,
 359                                                        true),
 360     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 361                                                  VIRTIO_SCSI_F_T10_PI,
 362                                                  false),
 363     DEFINE_PROP_END_OF_LIST(),
 364 };
 365
 366 static void vhost_user_scsi_reset(VirtIODevice *vdev)
 367 {
 368     VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
 369     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 370
 371     vhost_dev_free_inflight(vsc->inflight);
 372 }
 373
 374 static struct vhost_dev *vhost_user_scsi_get_vhost(VirtIODevice *vdev)
 375 {
 376     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
 377     return &vsc->dev;
 378 }
 379
 380 static const VMStateDescription vmstate_vhost_scsi = {
 381     .name = "virtio-scsi",
 382     .minimum_version_id = 1,
 383     .version_id = 1,
 384     .fields = (const VMStateField[]) {
 385         VMSTATE_VIRTIO_DEVICE,
 386         VMSTATE_END_OF_LIST()
 387     },
 388 };
 389
 390 static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
 391 {
 392     DeviceClass *dc = DEVICE_CLASS(klass);
 393     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 394     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 395
 396     device_class_set_props(dc, vhost_user_scsi_properties);
 397     dc->vmsd = &vmstate_vhost_scsi;
 398     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 399     vdc->realize = vhost_user_scsi_realize;
 400     vdc->unrealize = vhost_user_scsi_unrealize;
 401     vdc->get_features = vhost_scsi_common_get_features;
 402     vdc->set_config = vhost_scsi_common_set_config;
 403     vdc->set_status = vhost_user_scsi_set_status;
 404     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 405     vdc->reset = vhost_user_scsi_reset;
 406     vdc->get_vhost = vhost_user_scsi_get_vhost;
 407 }
 408
 409 static void vhost_user_scsi_instance_init(Object *obj)
 410 {
 411     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 412
 413     vsc->feature_bits = user_feature_bits;
 414
 415     /* Add the bootindex property for this object */
 416     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 417                                   DEVICE(vsc));
 418 }
 419
 420 static const TypeInfo vhost_user_scsi_info = {
 421     .name = TYPE_VHOST_USER_SCSI,
 422     .parent = TYPE_VHOST_SCSI_COMMON,
 423     .instance_size = sizeof(VHostUserSCSI),
 424     .class_init = vhost_user_scsi_class_init,
 425     .instance_init = vhost_user_scsi_instance_init,
 426     .interfaces = (InterfaceInfo[]) {
 427         { TYPE_FW_PATH_PROVIDER },
 428         { }
 429     },
 430 };
 431
 432 static void virtio_register_types(void)
 433 {
 434     type_register_static(&vhost_user_scsi_info);
 435 }
 436
 437 type_init(virtio_register_types)