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/fw-path-provider.h"
  30 #include "hw/qdev-properties.h"
  31 #include "qemu/cutils.h"
  32 #include "sysemu/sysemu.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     VIRTIO_F_RING_RESET,
  41     VHOST_INVALID_FEATURE_BIT
  42 };
  43
  44 static int vhost_scsi_set_endpoint(VHostSCSI *s)
  45 {
  46     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  47     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  48     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  49     struct vhost_scsi_target backend;
  50     int ret;
  51
  52     memset(&backend, 0, sizeof(backend));
  53     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  54     ret = vhost_ops->vhost_scsi_set_endpoint(&vsc->dev, &backend);
  55     if (ret < 0) {
  56         return -errno;
  57     }
  58     return 0;
  59 }
  60
  61 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  62 {
  63     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  64     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  65     struct vhost_scsi_target backend;
  66     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  67
  68     memset(&backend, 0, sizeof(backend));
  69     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  70     vhost_ops->vhost_scsi_clear_endpoint(&vsc->dev, &backend);
  71 }
  72
  73 static int vhost_scsi_start(VHostSCSI *s)
  74 {
  75     int ret, abi_version;
  76     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
  77     const VhostOps *vhost_ops = vsc->dev.vhost_ops;
  78
  79     ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &abi_version);
  80     if (ret < 0) {
  81         return -errno;
  82     }
  83     if (abi_version > VHOST_SCSI_ABI_VERSION) {
  84         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  85                      " %d is greater than vhost_scsi userspace supports: %d,"
  86                      " please upgrade your version of QEMU", abi_version,
  87                      VHOST_SCSI_ABI_VERSION);
  88         return -ENOSYS;
  89     }
  90
  91     ret = vhost_scsi_common_start(vsc);
  92     if (ret < 0) {
  93         return ret;
  94     }
  95
  96     ret = vhost_scsi_set_endpoint(s);
  97     if (ret < 0) {
  98         error_report("Error setting vhost-scsi endpoint");
  99         vhost_scsi_common_stop(vsc);
 100     }
 101
 102     return ret;
 103 }
 104
 105 static void vhost_scsi_stop(VHostSCSI *s)
 106 {
 107     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 108
 109     vhost_scsi_clear_endpoint(s);
 110     vhost_scsi_common_stop(vsc);
 111 }
 112
 113 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 114 {
 115     VHostSCSI *s = VHOST_SCSI(vdev);
 116     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 117     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 118
 119     if (!vdev->vm_running) {
 120         start = false;
 121     }
 122
 123     if (vhost_dev_is_started(&vsc->dev) == start) {
 124         return;
 125     }
 126
 127     if (start) {
 128         int ret;
 129
 130         ret = vhost_scsi_start(s);
 131         if (ret < 0) {
 132             error_report("unable to start vhost-scsi: %s", strerror(-ret));
 133             exit(1);
 134         }
 135     } else {
 136         vhost_scsi_stop(s);
 137     }
 138 }
 139
 140 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 141 {
 142 }
 143
 144 static int vhost_scsi_pre_save(void *opaque)
 145 {
 146     VHostSCSICommon *vsc = opaque;
 147
 148     /* At this point, backend must be stopped, otherwise
 149      * it might keep writing to memory. */
 150     assert(!vhost_dev_is_started(&vsc->dev));
 151
 152     return 0;
 153 }
 154
 155 static const VMStateDescription vmstate_virtio_vhost_scsi = {
 156     .name = "virtio-vhost_scsi",
 157     .minimum_version_id = 1,
 158     .version_id = 1,
 159     .fields = (VMStateField[]) {
 160         VMSTATE_VIRTIO_DEVICE,
 161         VMSTATE_END_OF_LIST()
 162     },
 163     .pre_save = vhost_scsi_pre_save,
 164 };
 165
 166 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 167 {
 168     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 169     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 170     Error *err = NULL;
 171     int vhostfd = -1;
 172     int ret;
 173     struct vhost_virtqueue *vqs = NULL;
 174
 175     if (!vs->conf.wwpn) {
 176         error_setg(errp, "vhost-scsi: missing wwpn");
 177         return;
 178     }
 179
 180     if (vs->conf.vhostfd) {
 181         vhostfd = monitor_fd_param(monitor_cur(), vs->conf.vhostfd, errp);
 182         if (vhostfd == -1) {
 183             error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
 184             return;
 185         }
 186     } else {
 187         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 188         if (vhostfd < 0) {
 189             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 190                        strerror(errno));
 191             return;
 192         }
 193     }
 194
 195     virtio_scsi_common_realize(dev,
 196                                vhost_dummy_handle_output,
 197                                vhost_dummy_handle_output,
 198                                vhost_dummy_handle_output,
 199                                &err);
 200     if (err != NULL) {
 201         error_propagate(errp, err);
 202         goto close_fd;
 203     }
 204
 205     if (!vsc->migratable) {
 206         error_setg(&vsc->migration_blocker,
 207                 "vhost-scsi does not support migration in all cases. "
 208                 "When external environment supports it (Orchestrator migrates "
 209                 "target SCSI device state or use shared storage over network), "
 210                 "set 'migratable' property to true to enable migration.");
 211         if (migrate_add_blocker(vsc->migration_blocker, errp) < 0) {
 212             goto free_virtio;
 213         }
 214     }
 215
 216     vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 217     vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
 218     vsc->dev.vqs = vqs;
 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, errp);
 224     if (ret < 0) {
 225         /*
 226          * vhost_dev_init calls vhost_dev_cleanup on error, which closes
 227          * vhostfd, don't double close it.
 228          */
 229         vhostfd = -1;
 230         goto free_vqs;
 231     }
 232
 233     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 234     vsc->channel = 0;
 235     vsc->lun = 0;
 236     /* Note: we can also get the minimum tpgt from kernel */
 237     vsc->target = vs->conf.boot_tpgt;
 238
 239     return;
 240
 241  free_vqs:
 242     g_free(vqs);
 243     if (!vsc->migratable) {
 244         migrate_del_blocker(vsc->migration_blocker);
 245     }
 246  free_virtio:
 247     error_free(vsc->migration_blocker);
 248     virtio_scsi_common_unrealize(dev);
 249  close_fd:
 250     if (vhostfd >= 0) {
 251         close(vhostfd);
 252     }
 253     return;
 254 }
 255
 256 static void vhost_scsi_unrealize(DeviceState *dev)
 257 {
 258     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 259     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 260     struct vhost_virtqueue *vqs = vsc->dev.vqs;
 261
 262     if (!vsc->migratable) {
 263         migrate_del_blocker(vsc->migration_blocker);
 264         error_free(vsc->migration_blocker);
 265     }
 266
 267     /* This will stop vhost backend. */
 268     vhost_scsi_set_status(vdev, 0);
 269
 270     vhost_dev_cleanup(&vsc->dev);
 271     g_free(vqs);
 272
 273     virtio_scsi_common_unrealize(dev);
 274 }
 275
 276 static struct vhost_dev *vhost_scsi_get_vhost(VirtIODevice *vdev)
 277 {
 278     VHostSCSI *s = VHOST_SCSI(vdev);
 279     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 280     return &vsc->dev;
 281 }
 282
 283 static Property vhost_scsi_properties[] = {
 284     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
 285     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
 286     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
 287     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
 288                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
 289     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
 290                        128),
 291     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
 292                       true),
 293     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 294                        0xFFFF),
 295     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 296     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 297                                                  VIRTIO_SCSI_F_T10_PI,
 298                                                  false),
 299     DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
 300     DEFINE_PROP_END_OF_LIST(),
 301 };
 302
 303 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 304 {
 305     DeviceClass *dc = DEVICE_CLASS(klass);
 306     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 307     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 308
 309     device_class_set_props(dc, vhost_scsi_properties);
 310     dc->vmsd = &vmstate_virtio_vhost_scsi;
 311     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 312     vdc->realize = vhost_scsi_realize;
 313     vdc->unrealize = vhost_scsi_unrealize;
 314     vdc->get_features = vhost_scsi_common_get_features;
 315     vdc->set_config = vhost_scsi_common_set_config;
 316     vdc->set_status = vhost_scsi_set_status;
 317     vdc->get_vhost = vhost_scsi_get_vhost;
 318     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 319 }
 320
 321 static void vhost_scsi_instance_init(Object *obj)
 322 {
 323     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 324
 325     vsc->feature_bits = kernel_feature_bits;
 326
 327     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 328                                   DEVICE(vsc));
 329 }
 330
 331 static const TypeInfo vhost_scsi_info = {
 332     .name = TYPE_VHOST_SCSI,
 333     .parent = TYPE_VHOST_SCSI_COMMON,
 334     .instance_size = sizeof(VHostSCSI),
 335     .class_init = vhost_scsi_class_init,
 336     .instance_init = vhost_scsi_instance_init,
 337     .interfaces = (InterfaceInfo[]) {
 338         { TYPE_FW_PATH_PROVIDER },
 339         { }
 340     },
 341 };
 342
 343 static void virtio_register_types(void)
 344 {
 345     type_register_static(&vhost_scsi_info);
 346 }
 347
 348 type_init(virtio_register_types)