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