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