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     const VhostOps *vhost_ops = s->dev.vhost_ops;
  40     struct vhost_scsi_target backend;
  41     int ret;
  42
  43     memset(&backend, 0, sizeof(backend));
  44     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  45     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
  46     if (ret < 0) {
  47         return -errno;
  48     }
  49     return 0;
  50 }
  51
  52 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  53 {
  54     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  55     struct vhost_scsi_target backend;
  56     const VhostOps *vhost_ops = s->dev.vhost_ops;
  57
  58     memset(&backend, 0, sizeof(backend));
  59     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  60     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
  61 }
  62
  63 static int vhost_scsi_start(VHostSCSI *s)
  64 {
  65     int ret, abi_version, i;
  66     VirtIODevice *vdev = VIRTIO_DEVICE(s);
  67     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
  68     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
  69     const VhostOps *vhost_ops = s->dev.vhost_ops;
  70
  71     if (!k->set_guest_notifiers) {
  72         error_report("binding does not support guest notifiers");
  73         return -ENOSYS;
  74     }
  75
  76     ret = vhost_ops->vhost_call(&s->dev,
  77                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
  78     if (ret < 0) {
  79         return -errno;
  80     }
  81     if (abi_version > VHOST_SCSI_ABI_VERSION) {
  82         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  83                      " %d is greater than vhost_scsi userspace supports: %d, please"
  84                      " upgrade your version of QEMU\n", abi_version,
  85                      VHOST_SCSI_ABI_VERSION);
  86         return -ENOSYS;
  87     }
  88
  89     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
  90     if (ret < 0) {
  91         return ret;
  92     }
  93
  94     s->dev.acked_features = vdev->guest_features;
  95     ret = vhost_dev_start(&s->dev, vdev);
  96     if (ret < 0) {
  97         error_report("Error start vhost dev");
  98         goto err_notifiers;
  99     }
 100
 101     ret = vhost_scsi_set_endpoint(s);
 102     if (ret < 0) {
 103         error_report("Error set vhost-scsi endpoint");
 104         goto err_vhost_stop;
 105     }
 106
 107     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 108     if (ret < 0) {
 109         error_report("Error binding guest notifier");
 110         goto err_endpoint;
 111     }
 112
 113     /* guest_notifier_mask/pending not used yet, so just unmask
 114      * everything here.  virtio-pci will do the right thing by
 115      * enabling/disabling irqfd.
 116      */
 117     for (i = 0; i < s->dev.nvqs; i++) {
 118         vhost_virtqueue_mask(&s->dev, vdev, i, false);
 119     }
 120
 121     return ret;
 122
 123 err_endpoint:
 124     vhost_scsi_clear_endpoint(s);
 125 err_vhost_stop:
 126     vhost_dev_stop(&s->dev, vdev);
 127 err_notifiers:
 128     vhost_dev_disable_notifiers(&s->dev, vdev);
 129     return ret;
 130 }
 131
 132 static void vhost_scsi_stop(VHostSCSI *s)
 133 {
 134     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 135     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 136     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 137     int ret = 0;
 138
 139     if (k->set_guest_notifiers) {
 140         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 141         if (ret < 0) {
 142                 error_report("vhost guest notifier cleanup failed: %d\n", ret);
 143         }
 144     }
 145     assert(ret >= 0);
 146
 147     vhost_scsi_clear_endpoint(s);
 148     vhost_dev_stop(&s->dev, vdev);
 149     vhost_dev_disable_notifiers(&s->dev, vdev);
 150 }
 151
 152 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
 153                                         uint32_t features)
 154 {
 155     VHostSCSI *s = VHOST_SCSI(vdev);
 156
 157     return vhost_get_features(&s->dev, kernel_feature_bits, features);
 158 }
 159
 160 static void vhost_scsi_set_config(VirtIODevice *vdev,
 161                                   const uint8_t *config)
 162 {
 163     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 164     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 165
 166     if ((uint32_t) ldl_p(&scsiconf->sense_size) != vs->sense_size ||
 167         (uint32_t) ldl_p(&scsiconf->cdb_size) != vs->cdb_size) {
 168         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
 169         exit(1);
 170     }
 171 }
 172
 173 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 174 {
 175     VHostSCSI *s = (VHostSCSI *)vdev;
 176     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 177
 178     if (s->dev.started == start) {
 179         return;
 180     }
 181
 182     if (start) {
 183         int ret;
 184
 185         ret = vhost_scsi_start(s);
 186         if (ret < 0) {
 187             error_report("virtio-scsi: unable to start vhost: %s\n",
 188                          strerror(-ret));
 189
 190             /* There is no userspace virtio-scsi fallback so exit */
 191             exit(1);
 192         }
 193     } else {
 194         vhost_scsi_stop(s);
 195     }
 196 }
 197
 198 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 199 {
 200 }
 201
 202 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 203 {
 204     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 205     VHostSCSI *s = VHOST_SCSI(dev);
 206     Error *err = NULL;
 207     int vhostfd = -1;
 208     int ret;
 209
 210     if (!vs->conf.wwpn) {
 211         error_setg(errp, "vhost-scsi: missing wwpn");
 212         return;
 213     }
 214
 215     if (vs->conf.vhostfd) {
 216         vhostfd = monitor_handle_fd_param(cur_mon, vs->conf.vhostfd);
 217         if (vhostfd == -1) {
 218             error_setg(errp, "vhost-scsi: unable to parse vhostfd");
 219             return;
 220         }
 221     } else {
 222         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 223         if (vhostfd < 0) {
 224             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 225                        strerror(errno));
 226             return;
 227         }
 228     }
 229
 230     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
 231                                vhost_dummy_handle_output,
 232                                vhost_dummy_handle_output);
 233     if (err != NULL) {
 234         error_propagate(errp, err);
 235         return;
 236     }
 237
 238     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 239     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 240     s->dev.vq_index = 0;
 241
 242     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
 243                          VHOST_BACKEND_TYPE_KERNEL, true);
 244     if (ret < 0) {
 245         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 246                    strerror(-ret));
 247         return;
 248     }
 249     s->dev.backend_features = 0;
 250
 251     error_setg(&s->migration_blocker,
 252             "vhost-scsi does not support migration");
 253     migrate_add_blocker(s->migration_blocker);
 254 }
 255
 256 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 257 {
 258     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 259     VHostSCSI *s = VHOST_SCSI(dev);
 260
 261     migrate_del_blocker(s->migration_blocker);
 262     error_free(s->migration_blocker);
 263
 264     /* This will stop vhost backend. */
 265     vhost_scsi_set_status(vdev, 0);
 266
 267     g_free(s->dev.vqs);
 268
 269     virtio_scsi_common_unrealize(dev, errp);
 270 }
 271
 272 static Property vhost_scsi_properties[] = {
 273     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
 274     DEFINE_PROP_END_OF_LIST(),
 275 };
 276
 277 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 278 {
 279     DeviceClass *dc = DEVICE_CLASS(klass);
 280     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 281
 282     dc->props = vhost_scsi_properties;
 283     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 284     vdc->realize = vhost_scsi_realize;
 285     vdc->unrealize = vhost_scsi_unrealize;
 286     vdc->get_features = vhost_scsi_get_features;
 287     vdc->set_config = vhost_scsi_set_config;
 288     vdc->set_status = vhost_scsi_set_status;
 289 }
 290
 291 static const TypeInfo vhost_scsi_info = {
 292     .name = TYPE_VHOST_SCSI,
 293     .parent = TYPE_VIRTIO_SCSI_COMMON,
 294     .instance_size = sizeof(VHostSCSI),
 295     .class_init = vhost_scsi_class_init,
 296 };
 297
 298 static void virtio_register_types(void)
 299 {
 300     type_register_static(&vhost_scsi_info);
 301 }
 302
 303 type_init(virtio_register_types)