qemu/hw/scsi/vhost-scsi.c
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   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 "hw/qdev-properties.h"
  32#include "qemu/cutils.h"
  33#include "sysemu/sysemu.h"
  34
  35/* Features supported by host kernel. */
  36static const int kernel_feature_bits[] = {
  37    VIRTIO_F_NOTIFY_ON_EMPTY,
  38    VIRTIO_RING_F_INDIRECT_DESC,
  39    VIRTIO_RING_F_EVENT_IDX,
  40    VIRTIO_SCSI_F_HOTPLUG,
  41    VHOST_INVALID_FEATURE_BIT
  42};
  43
  44static 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
  61static 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
  73static 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
 105static 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
 113static 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 (vsc->dev.started == 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
 140static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 141{
 142}
 143
 144static 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(!vsc->dev.started);
 151
 152    return 0;
 153}
 154
 155static 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
 166static 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
 174    if (!vs->conf.wwpn) {
 175        error_setg(errp, "vhost-scsi: missing wwpn");
 176        return;
 177    }
 178
 179    if (vs->conf.vhostfd) {
 180        vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp);
 181        if (vhostfd == -1) {
 182            error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
 183            return;
 184        }
 185    } else {
 186        vhostfd = open("/dev/vhost-scsi", O_RDWR);
 187        if (vhostfd < 0) {
 188            error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 189                       strerror(errno));
 190            return;
 191        }
 192    }
 193
 194    virtio_scsi_common_realize(dev,
 195                               vhost_dummy_handle_output,
 196                               vhost_dummy_handle_output,
 197                               vhost_dummy_handle_output,
 198                               &err);
 199    if (err != NULL) {
 200        error_propagate(errp, err);
 201        goto close_fd;
 202    }
 203
 204    if (!vsc->migratable) {
 205        error_setg(&vsc->migration_blocker,
 206                "vhost-scsi does not support migration in all cases. "
 207                "When external environment supports it (Orchestrator migrates "
 208                "target SCSI device state or use shared storage over network), "
 209                "set 'migratable' property to true to enable migration.");
 210        if (migrate_add_blocker(vsc->migration_blocker, errp) < 0) {
 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
 249static void vhost_scsi_unrealize(DeviceState *dev)
 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
 269static 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_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
 277                      true),
 278    DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 279                       0xFFFF),
 280    DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 281    DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 282                                                 VIRTIO_SCSI_F_T10_PI,
 283                                                 false),
 284    DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
 285    DEFINE_PROP_END_OF_LIST(),
 286};
 287
 288static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 289{
 290    DeviceClass *dc = DEVICE_CLASS(klass);
 291    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 292    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 293
 294    device_class_set_props(dc, vhost_scsi_properties);
 295    dc->vmsd = &vmstate_virtio_vhost_scsi;
 296    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 297    vdc->realize = vhost_scsi_realize;
 298    vdc->unrealize = vhost_scsi_unrealize;
 299    vdc->get_features = vhost_scsi_common_get_features;
 300    vdc->set_config = vhost_scsi_common_set_config;
 301    vdc->set_status = vhost_scsi_set_status;
 302    fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 303}
 304
 305static void vhost_scsi_instance_init(Object *obj)
 306{
 307    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 308
 309    vsc->feature_bits = kernel_feature_bits;
 310
 311    device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 312                                  DEVICE(vsc));
 313}
 314
 315static const TypeInfo vhost_scsi_info = {
 316    .name = TYPE_VHOST_SCSI,
 317    .parent = TYPE_VHOST_SCSI_COMMON,
 318    .instance_size = sizeof(VHostSCSI),
 319    .class_init = vhost_scsi_class_init,
 320    .instance_init = vhost_scsi_instance_init,
 321    .interfaces = (InterfaceInfo[]) {
 322        { TYPE_FW_PATH_PROVIDER },
 323        { }
 324    },
 325};
 326
 327static void virtio_register_types(void)
 328{
 329    type_register_static(&vhost_scsi_info);
 330}
 331
 332type_init(virtio_register_types)
 333