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