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
  27 /* Features supported by host kernel. */
  28 static const int kernel_feature_bits[] = {
  29     VIRTIO_F_NOTIFY_ON_EMPTY,
  30     VIRTIO_RING_F_INDIRECT_DESC,
  31     VIRTIO_RING_F_EVENT_IDX,
  32     VIRTIO_SCSI_F_HOTPLUG,
  33     VHOST_INVALID_FEATURE_BIT
  34 };
  35
  36 static int vhost_scsi_set_endpoint(VHostSCSI *s)
  37 {
  38     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  39     struct vhost_scsi_target backend;
  40     int ret;
  41
  42     memset(&backend, 0, sizeof(backend));
  43     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  44     ret = ioctl(s->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
  45     if (ret < 0) {
  46         return -errno;
  47     }
  48     return 0;
  49 }
  50
  51 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  52 {
  53     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  54     struct vhost_scsi_target backend;
  55
  56     memset(&backend, 0, sizeof(backend));
  57     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  58     ioctl(s->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
  59 }
  60
  61 static int vhost_scsi_start(VHostSCSI *s)
  62 {
  63     int ret, abi_version, i;
  64     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  65     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
  66     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
  67
  68     if (!k->set_guest_notifiers) {
  69         error_report("binding does not support guest notifiers");
  70         return -ENOSYS;
  71     }
  72
  73     ret = ioctl(s->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
  74     if (ret < 0) {
  75         return -errno;
  76     }
  77     if (abi_version > VHOST_SCSI_ABI_VERSION) {
  78         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  79                      " %d is greater than vhost_scsi userspace supports: %d, please"
  80                      " upgrade your version of QEMU\n", abi_version,
  81                      VHOST_SCSI_ABI_VERSION);
  82         return -ENOSYS;
  83     }
  84
  85     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
  86     if (ret < 0) {
  87         return ret;
  88     }
  89
  90     s->dev.acked_features = vdev->guest_features;
  91     ret = vhost_dev_start(&s->dev, vdev);
  92     if (ret < 0) {
  93         error_report("Error start vhost dev");
  94         goto err_notifiers;
  95     }
  96
  97     ret = vhost_scsi_set_endpoint(s);
  98     if (ret < 0) {
  99         error_report("Error set vhost-scsi endpoint");
 100         goto err_vhost_stop;
 101     }
 102
 103     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 104     if (ret < 0) {
 105         error_report("Error binding guest notifier");
 106         goto err_endpoint;
 107     }
 108
 109     /* guest_notifier_mask/pending not used yet, so just unmask
 110      * everything here.  virtio-pci will do the right thing by
 111      * enabling/disabling irqfd.
 112      */
 113     for (i = 0; i < s->dev.nvqs; i++) {
 114         vhost_virtqueue_mask(&s->dev, vdev, i, false);
 115     }
 116
 117     return ret;
 118
 119 err_endpoint:
 120     vhost_scsi_clear_endpoint(s);
 121 err_vhost_stop:
 122     vhost_dev_stop(&s->dev, vdev);
 123 err_notifiers:
 124     vhost_dev_disable_notifiers(&s->dev, vdev);
 125     return ret;
 126 }
 127
 128 static void vhost_scsi_stop(VHostSCSI *s)
 129 {
 130     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 131     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 132     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 133     int ret = 0;
 134
 135     if (k->set_guest_notifiers) {
 136         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 137         if (ret < 0) {
 138                 error_report("vhost guest notifier cleanup failed: %d\n", ret);
 139         }
 140     }
 141     assert(ret >= 0);
 142
 143     vhost_scsi_clear_endpoint(s);
 144     vhost_dev_stop(&s->dev, vdev);
 145     vhost_dev_disable_notifiers(&s->dev, vdev);
 146 }
 147
 148 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
 149                                         uint32_t features)
 150 {
 151     VHostSCSI *s = VHOST_SCSI(vdev);
 152
 153     return vhost_get_features(&s->dev, kernel_feature_bits, features);
 154 }
 155
 156 static void vhost_scsi_set_config(VirtIODevice *vdev,
 157                                   const uint8_t *config)
 158 {
 159     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 160     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 161
 162     if ((uint32_t) ldl_p(&scsiconf->sense_size) != vs->sense_size ||
 163         (uint32_t) ldl_p(&scsiconf->cdb_size) != vs->cdb_size) {
 164         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
 165         exit(1);
 166     }
 167 }
 168
 169 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 170 {
 171     VHostSCSI *s = (VHostSCSI *)vdev;
 172     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 173
 174     if (s->dev.started == start) {
 175         return;
 176     }
 177
 178     if (start) {
 179         int ret;
 180
 181         ret = vhost_scsi_start(s);
 182         if (ret < 0) {
 183             error_report("virtio-scsi: unable to start vhost: %s\n",
 184                          strerror(-ret));
 185
 186             /* There is no userspace virtio-scsi fallback so exit */
 187             exit(1);
 188         }
 189     } else {
 190         vhost_scsi_stop(s);
 191     }
 192 }
 193
 194 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 195 {
 196     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 197     VHostSCSI *s = VHOST_SCSI(dev);
 198     Error *err = NULL;
 199     int vhostfd = -1;
 200     int ret;
 201
 202     if (!vs->conf.wwpn) {
 203         error_setg(errp, "vhost-scsi: missing wwpn");
 204         return;
 205     }
 206
 207     if (vs->conf.vhostfd) {
 208         vhostfd = monitor_handle_fd_param(cur_mon, vs->conf.vhostfd);
 209         if (vhostfd == -1) {
 210             error_setg(errp, "vhost-scsi: unable to parse vhostfd");
 211             return;
 212         }
 213     } else {
 214         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 215         if (vhostfd < 0) {
 216             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 217                        strerror(errno));
 218             return;
 219         }
 220     }
 221
 222     virtio_scsi_common_realize(dev, &err);
 223     if (err != NULL) {
 224         error_propagate(errp, err);
 225         return;
 226     }
 227
 228     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 229     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 230     s->dev.vq_index = 0;
 231
 232     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
 233                          true);
 234     if (ret < 0) {
 235         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 236                    strerror(-ret));
 237         return;
 238     }
 239     s->dev.backend_features = 0;
 240
 241     error_setg(&s->migration_blocker,
 242             "vhost-scsi does not support migration");
 243     migrate_add_blocker(s->migration_blocker);
 244 }
 245
 246 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 247 {
 248     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 249     VHostSCSI *s = VHOST_SCSI(dev);
 250
 251     migrate_del_blocker(s->migration_blocker);
 252     error_free(s->migration_blocker);
 253
 254     /* This will stop vhost backend. */
 255     vhost_scsi_set_status(vdev, 0);
 256
 257     g_free(s->dev.vqs);
 258
 259     virtio_scsi_common_unrealize(dev, errp);
 260 }
 261
 262 static Property vhost_scsi_properties[] = {
 263     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
 264     DEFINE_PROP_END_OF_LIST(),
 265 };
 266
 267 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 268 {
 269     DeviceClass *dc = DEVICE_CLASS(klass);
 270     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 271
 272     dc->props = vhost_scsi_properties;
 273     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 274     vdc->realize = vhost_scsi_realize;
 275     vdc->unrealize = vhost_scsi_unrealize;
 276     vdc->get_features = vhost_scsi_get_features;
 277     vdc->set_config = vhost_scsi_set_config;
 278     vdc->set_status = vhost_scsi_set_status;
 279 }
 280
 281 static const TypeInfo vhost_scsi_info = {
 282     .name = TYPE_VHOST_SCSI,
 283     .parent = TYPE_VIRTIO_SCSI_COMMON,
 284     .instance_size = sizeof(VHostSCSI),
 285     .class_init = vhost_scsi_class_init,
 286 };
 287
 288 static void virtio_register_types(void)
 289 {
 290     type_register_static(&vhost_scsi_info);
 291 }
 292
 293 type_init(virtio_register_types)