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 <linux/vhost.h>
  19 #include <sys/ioctl.h>
  20 #include "qapi/error.h"
  21 #include "qemu/error-report.h"
  22 #include "qemu/module.h"
  23 #include "qemu/queue.h"
  24 #include "monitor/monitor.h"
  25 #include "migration/blocker.h"
  26 #include "hw/virtio/vhost-scsi.h"
  27 #include "hw/virtio/vhost.h"
  28 #include "hw/virtio/virtio-scsi.h"
  29 #include "hw/virtio/virtio-bus.h"
  30 #include "hw/virtio/virtio-access.h"
  31 #include "hw/fw-path-provider.h"
  32 #include "qemu/cutils.h"
  33
  34 /* Features supported by host kernel. */
  35 static const int kernel_feature_bits[] = {
  36     VIRTIO_F_NOTIFY_ON_EMPTY,
  37     VIRTIO_RING_F_INDIRECT_DESC,
  38     VIRTIO_RING_F_EVENT_IDX,
  39     VIRTIO_SCSI_F_HOTPLUG,
  40     VHOST_INVALID_FEATURE_BIT
  41 };
  42
  43 static int vhost_scsi_set_endpoint(VHostSCSI *s)
  44 {
  45     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  46     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  47     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  48     struct vhost_scsi_target backend;
  49     int ret;
  50
  51     memset(&backend, 0, sizeof(backend));
  52     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  53     ret = vhost_ops->vhost_scsi_set_endpoint(&vsc->dev, &backend);
  54     if (ret < 0) {
  55         return -errno;
  56     }
  57     return 0;
  58 }
  59
  60 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  61 {
  62     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  63     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  64     struct vhost_scsi_target backend;
  65     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  66
  67     memset(&backend, 0, sizeof(backend));
  68     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  69     vhost_ops->vhost_scsi_clear_endpoint(&vsc->dev, &backend);
  70 }
  71
  72 static int vhost_scsi_start(VHostSCSI *s)
  73 {
  74     int ret, abi_version;
  75     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  76     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  77
  78     ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &abi_version);
  79     if (ret < 0) {
  80         return -errno;
  81     }
  82     if (abi_version > VHOST_SCSI_ABI_VERSION) {
  83         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  84                      " %d is greater than vhost_scsi userspace supports: %d,"
  85                      " please upgrade your version of QEMU", abi_version,
  86                      VHOST_SCSI_ABI_VERSION);
  87         return -ENOSYS;
  88     }
  89
  90     ret = vhost_scsi_common_start(vsc);
  91     if (ret < 0) {
  92         return ret;
  93     }
  94
  95     ret = vhost_scsi_set_endpoint(s);
  96     if (ret < 0) {
  97         error_report("Error setting vhost-scsi endpoint");
  98         vhost_scsi_common_stop(vsc);
  99     }
 100
 101     return ret;
 102 }
 103
 104 static void vhost_scsi_stop(VHostSCSI *s)
 105 {
 106     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 107
 108     vhost_scsi_clear_endpoint(s);
 109     vhost_scsi_common_stop(vsc);
 110 }
 111
 112 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 113 {
 114     VHostSCSI *s = VHOST_SCSI(vdev);
 115     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 116     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 117
 118     if (!vdev->vm_running) {
 119         start = false;
 120     }
 121
 122     if (vsc->dev.started == start) {
 123         return;
 124     }
 125
 126     if (start) {
 127         int ret;
 128
 129         ret = vhost_scsi_start(s);
 130         if (ret < 0) {
 131             error_report("unable to start vhost-scsi: %s", strerror(-ret));
 132             exit(1);
 133         }
 134     } else {
 135         vhost_scsi_stop(s);
 136     }
 137 }
 138
 139 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 140 {
 141 }
 142
 143 static int vhost_scsi_pre_save(void *opaque)
 144 {
 145     VHostSCSICommon *vsc = opaque;
 146
 147     /* At this point, backend must be stopped, otherwise
 148      * it might keep writing to memory. */
 149     assert(!vsc->dev.started);
 150
 151     return 0;
 152 }
 153
 154 static const VMStateDescription vmstate_virtio_vhost_scsi = {
 155     .name = "virtio-vhost_scsi",
 156     .minimum_version_id = 1,
 157     .version_id = 1,
 158     .fields = (VMStateField[]) {
 159         VMSTATE_VIRTIO_DEVICE,
 160         VMSTATE_END_OF_LIST()
 161     },
 162     .pre_save = vhost_scsi_pre_save,
 163 };
 164
 165 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 166 {
 167     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 168     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 169     Error *err = NULL;
 170     int vhostfd = -1;
 171     int ret;
 172
 173     if (!vs->conf.wwpn) {
 174         error_setg(errp, "vhost-scsi: missing wwpn");
 175         return;
 176     }
 177
 178     if (vs->conf.vhostfd) {
 179         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp);
 180         if (vhostfd == -1) {
 181             error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
 182             return;
 183         }
 184     } else {
 185         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 186         if (vhostfd < 0) {
 187             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 188                        strerror(errno));
 189             return;
 190         }
 191     }
 192
 193     virtio_scsi_common_realize(dev,
 194                                vhost_dummy_handle_output,
 195                                vhost_dummy_handle_output,
 196                                vhost_dummy_handle_output,
 197                                &err);
 198     if (err != NULL) {
 199         error_propagate(errp, err);
 200         goto close_fd;
 201     }
 202
 203     if (!vsc->migratable) {
 204         error_setg(&vsc->migration_blocker,
 205                 "vhost-scsi does not support migration in all cases. "
 206                 "When external environment supports it (Orchestrator migrates "
 207                 "target SCSI device state or use shared storage over network), "
 208                 "set 'migratable' property to true to enable migration.");
 209         migrate_add_blocker(vsc->migration_blocker, &err);
 210         if (err) {
 211             error_propagate(errp, err);
 212             error_free(vsc->migration_blocker);
 213             goto close_fd;
 214         }
 215     }
 216
 217     vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 218     vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
 219     vsc->dev.vq_index = 0;
 220     vsc->dev.backend_features = 0;
 221
 222     ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
 223                          VHOST_BACKEND_TYPE_KERNEL, 0);
 224     if (ret < 0) {
 225         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 226                    strerror(-ret));
 227         goto free_vqs;
 228     }
 229
 230     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 231     vsc->channel = 0;
 232     vsc->lun = 0;
 233     /* Note: we can also get the minimum tpgt from kernel */
 234     vsc->target = vs->conf.boot_tpgt;
 235
 236     return;
 237
 238  free_vqs:
 239     if (!vsc->migratable) {
 240         migrate_del_blocker(vsc->migration_blocker);
 241     }
 242     g_free(vsc->dev.vqs);
 243  close_fd:
 244     close(vhostfd);
 245     return;
 246 }
 247
 248 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 249 {
 250     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 251     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 252     struct vhost_virtqueue *vqs = vsc->dev.vqs;
 253
 254     if (!vsc->migratable) {
 255         migrate_del_blocker(vsc->migration_blocker);
 256         error_free(vsc->migration_blocker);
 257     }
 258
 259     /* This will stop vhost backend. */
 260     vhost_scsi_set_status(vdev, 0);
 261
 262     vhost_dev_cleanup(&vsc->dev);
 263     g_free(vqs);
 264
 265     virtio_scsi_common_unrealize(dev, errp);
 266 }
 267
 268 static Property vhost_scsi_properties[] = {
 269     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
 270     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
 271     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
 272     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
 273     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
 274                        128),
 275     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 276                        0xFFFF),
 277     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 278     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 279                                                  VIRTIO_SCSI_F_T10_PI,
 280                                                  false),
 281     DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
 282     DEFINE_PROP_END_OF_LIST(),
 283 };
 284
 285 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 286 {
 287     DeviceClass *dc = DEVICE_CLASS(klass);
 288     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 289     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 290
 291     dc->props = vhost_scsi_properties;
 292     dc->vmsd = &vmstate_virtio_vhost_scsi;
 293     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 294     vdc->realize = vhost_scsi_realize;
 295     vdc->unrealize = vhost_scsi_unrealize;
 296     vdc->get_features = vhost_scsi_common_get_features;
 297     vdc->set_config = vhost_scsi_common_set_config;
 298     vdc->set_status = vhost_scsi_set_status;
 299     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 300 }
 301
 302 static void vhost_scsi_instance_init(Object *obj)
 303 {
 304     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 305
 306     vsc->feature_bits = kernel_feature_bits;
 307
 308     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 309                                   DEVICE(vsc), NULL);
 310 }
 311
 312 static const TypeInfo vhost_scsi_info = {
 313     .name = TYPE_VHOST_SCSI,
 314     .parent = TYPE_VHOST_SCSI_COMMON,
 315     .instance_size = sizeof(VHostSCSI),
 316     .class_init = vhost_scsi_class_init,
 317     .instance_init = vhost_scsi_instance_init,
 318     .interfaces = (InterfaceInfo[]) {
 319         { TYPE_FW_PATH_PROVIDER },
 320         { }
 321     },
 322 };
 323
 324 static void virtio_register_types(void)
 325 {
 326     type_register_static(&vhost_scsi_info);
 327 }
 328
 329 type_init(virtio_register_types)