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