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