hw/scsi/vhost-scsi.c

   1 /*
   2  * vhost_scsi host device
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
   8  *
   9  * Changes for QEMU mainline + tcm_vhost kernel upstream:
  10  *  Nicholas Bellinger <nab@risingtidesystems.com>
  11  *
  12  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  13  * See the COPYING.LIB file in the top-level directory.
  14  *
  15  */
  16
  17 #include <sys/ioctl.h>
  18 #include "config.h"
  19 #include "qemu/error-report.h"
  20 #include "qemu/queue.h"
  21 #include "monitor/monitor.h"
  22 #include "migration/migration.h"
  23 #include "hw/virtio/vhost-scsi.h"
  24 #include "hw/virtio/vhost.h"
  25 #include "hw/virtio/virtio-scsi.h"
  26 #include "hw/virtio/virtio-bus.h"
  27 #include "hw/virtio/virtio-access.h"
  28 #include "hw/fw-path-provider.h"
  29 #include "linux/vhost.h"
  30
  31 /* Features supported by host kernel. */
  32 static const int kernel_feature_bits[] = {
  33     VIRTIO_F_NOTIFY_ON_EMPTY,
  34     VIRTIO_RING_F_INDIRECT_DESC,
  35     VIRTIO_RING_F_EVENT_IDX,
  36     VIRTIO_SCSI_F_HOTPLUG,
  37     VHOST_INVALID_FEATURE_BIT
  38 };
  39
  40 static int vhost_scsi_set_endpoint(VHostSCSI *s)
  41 {
  42     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  43     const VhostOps *vhost_ops = s->dev.vhost_ops;
  44     struct vhost_scsi_target backend;
  45     int ret;
  46
  47     memset(&backend, 0, sizeof(backend));
  48     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  49     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
  50     if (ret < 0) {
  51         return -errno;
  52     }
  53     return 0;
  54 }
  55
  56 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  57 {
  58     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  59     struct vhost_scsi_target backend;
  60     const VhostOps *vhost_ops = s->dev.vhost_ops;
  61
  62     memset(&backend, 0, sizeof(backend));
  63     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  64     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
  65 }
  66
  67 static int vhost_scsi_start(VHostSCSI *s)
  68 {
  69     int ret, abi_version, i;
  70     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  71     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
  72     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
  73     const VhostOps *vhost_ops = s->dev.vhost_ops;
  74
  75     if (!k->set_guest_notifiers) {
  76         error_report("binding does not support guest notifiers");
  77         return -ENOSYS;
  78     }
  79
  80     ret = vhost_ops->vhost_call(&s->dev,
  81                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
  82     if (ret < 0) {
  83         return -errno;
  84     }
  85     if (abi_version > VHOST_SCSI_ABI_VERSION) {
  86         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  87                      " %d is greater than vhost_scsi userspace supports: %d, please"
  88                      " upgrade your version of QEMU", abi_version,
  89                      VHOST_SCSI_ABI_VERSION);
  90         return -ENOSYS;
  91     }
  92
  93     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
  94     if (ret < 0) {
  95         return ret;
  96     }
  97
  98     s->dev.acked_features = vdev->guest_features;
  99     ret = vhost_dev_start(&s->dev, vdev);
 100     if (ret < 0) {
 101         error_report("Error start vhost dev");
 102         goto err_notifiers;
 103     }
 104
 105     ret = vhost_scsi_set_endpoint(s);
 106     if (ret < 0) {
 107         error_report("Error set vhost-scsi endpoint");
 108         goto err_vhost_stop;
 109     }
 110
 111     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 112     if (ret < 0) {
 113         error_report("Error binding guest notifier");
 114         goto err_endpoint;
 115     }
 116
 117     /* guest_notifier_mask/pending not used yet, so just unmask
 118      * everything here.  virtio-pci will do the right thing by
 119      * enabling/disabling irqfd.
 120      */
 121     for (i = 0; i < s->dev.nvqs; i++) {
 122         vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
 123     }
 124
 125     return ret;
 126
 127 err_endpoint:
 128     vhost_scsi_clear_endpoint(s);
 129 err_vhost_stop:
 130     vhost_dev_stop(&s->dev, vdev);
 131 err_notifiers:
 132     vhost_dev_disable_notifiers(&s->dev, vdev);
 133     return ret;
 134 }
 135
 136 static void vhost_scsi_stop(VHostSCSI *s)
 137 {
 138     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 139     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 140     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 141     int ret = 0;
 142
 143     if (k->set_guest_notifiers) {
 144         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 145         if (ret < 0) {
 146                 error_report("vhost guest notifier cleanup failed: %d", ret);
 147         }
 148     }
 149     assert(ret >= 0);
 150
 151     vhost_scsi_clear_endpoint(s);
 152     vhost_dev_stop(&s->dev, vdev);
 153     vhost_dev_disable_notifiers(&s->dev, vdev);
 154 }
 155
 156 static uint64_t vhost_scsi_get_features(VirtIODevice *vdev,
 157                                         uint64_t features,
 158                                         Error **errp)
 159 {
 160     VHostSCSI *s = VHOST_SCSI(vdev);
 161
 162     return vhost_get_features(&s->dev, kernel_feature_bits, features);
 163 }
 164
 165 static void vhost_scsi_set_config(VirtIODevice *vdev,
 166                                   const uint8_t *config)
 167 {
 168     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 169     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 170
 171     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
 172         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
 173         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
 174         exit(1);
 175     }
 176 }
 177
 178 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 179 {
 180     VHostSCSI *s = (VHostSCSI *)vdev;
 181     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 182
 183     if (s->dev.started == start) {
 184         return;
 185     }
 186
 187     if (start) {
 188         int ret;
 189
 190         ret = vhost_scsi_start(s);
 191         if (ret < 0) {
 192             error_report("virtio-scsi: unable to start vhost: %s",
 193                          strerror(-ret));
 194
 195             /* There is no userspace virtio-scsi fallback so exit */
 196             exit(1);
 197         }
 198     } else {
 199         vhost_scsi_stop(s);
 200     }
 201 }
 202
 203 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 204 {
 205 }
 206
 207 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 208 {
 209     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 210     VHostSCSI *s = VHOST_SCSI(dev);
 211     Error *err = NULL;
 212     int vhostfd = -1;
 213     int ret;
 214
 215     if (!vs->conf.wwpn) {
 216         error_setg(errp, "vhost-scsi: missing wwpn");
 217         return;
 218     }
 219
 220     if (vs->conf.vhostfd) {
 221         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
 222         if (vhostfd == -1) {
 223             error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
 224                        error_get_pretty(err));
 225             error_free(err);
 226             return;
 227         }
 228     } else {
 229         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 230         if (vhostfd < 0) {
 231             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 232                        strerror(errno));
 233             return;
 234         }
 235     }
 236
 237     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
 238                                vhost_dummy_handle_output,
 239                                vhost_dummy_handle_output);
 240     if (err != NULL) {
 241         error_propagate(errp, err);
 242         close(vhostfd);
 243         return;
 244     }
 245
 246     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 247     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 248     s->dev.vq_index = 0;
 249     s->dev.backend_features = 0;
 250
 251     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
 252                          VHOST_BACKEND_TYPE_KERNEL);
 253     if (ret < 0) {
 254         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 255                    strerror(-ret));
 256         return;
 257     }
 258
 259     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 260     s->channel = 0;
 261     s->lun = 0;
 262     /* Note: we can also get the minimum tpgt from kernel */
 263     s->target = vs->conf.boot_tpgt;
 264
 265     error_setg(&s->migration_blocker,
 266             "vhost-scsi does not support migration");
 267     migrate_add_blocker(s->migration_blocker);
 268 }
 269
 270 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 271 {
 272     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 273     VHostSCSI *s = VHOST_SCSI(dev);
 274
 275     migrate_del_blocker(s->migration_blocker);
 276     error_free(s->migration_blocker);
 277
 278     /* This will stop vhost backend. */
 279     vhost_scsi_set_status(vdev, 0);
 280
 281     vhost_dev_cleanup(&s->dev);
 282     g_free(s->dev.vqs);
 283
 284     virtio_scsi_common_unrealize(dev, errp);
 285 }
 286
 287 /*
 288  * Implementation of an interface to adjust firmware path
 289  * for the bootindex property handling.
 290  */
 291 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
 292                                         DeviceState *dev)
 293 {
 294     VHostSCSI *s = VHOST_SCSI(dev);
 295     /* format: channel@channel/vhost-scsi@target,lun */
 296     return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel,
 297                            qdev_fw_name(dev), s->target, s->lun);
 298 }
 299
 300 static Property vhost_scsi_properties[] = {
 301     DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
 302     DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
 303     DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
 304     DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
 305     DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
 306                                                  0xFFFF),
 307     DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
 308                                                  128),
 309     DEFINE_PROP_END_OF_LIST(),
 310 };
 311
 312 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 313 {
 314     DeviceClass *dc = DEVICE_CLASS(klass);
 315     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 316     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 317
 318     dc->props = vhost_scsi_properties;
 319     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 320     vdc->realize = vhost_scsi_realize;
 321     vdc->unrealize = vhost_scsi_unrealize;
 322     vdc->get_features = vhost_scsi_get_features;
 323     vdc->set_config = vhost_scsi_set_config;
 324     vdc->set_status = vhost_scsi_set_status;
 325     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
 326 }
 327
 328 static void vhost_scsi_instance_init(Object *obj)
 329 {
 330     VHostSCSI *dev = VHOST_SCSI(obj);
 331
 332     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
 333                                   DEVICE(dev), NULL);
 334 }
 335
 336 static const TypeInfo vhost_scsi_info = {
 337     .name = TYPE_VHOST_SCSI,
 338     .parent = TYPE_VIRTIO_SCSI_COMMON,
 339     .instance_size = sizeof(VHostSCSI),
 340     .class_init = vhost_scsi_class_init,
 341     .instance_init = vhost_scsi_instance_init,
 342     .interfaces = (InterfaceInfo[]) {
 343         { TYPE_FW_PATH_PROVIDER },
 344         { }
 345     },
 346 };
 347
 348 static void virtio_register_types(void)
 349 {
 350     type_register_static(&vhost_scsi_info);
 351 }
 352
 353 type_init(virtio_register_types)