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/queue.h"
  23#include "monitor/monitor.h"
  24#include "migration/migration.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. */
  34static 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
  42static int vhost_scsi_set_endpoint(VHostSCSI *s)
  43{
  44    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  45    const VhostOps *vhost_ops = s->dev.vhost_ops;
  46    struct vhost_scsi_target backend;
  47    int ret;
  48
  49    memset(&backend, 0, sizeof(backend));
  50    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  51    ret = vhost_ops->vhost_scsi_set_endpoint(&s->dev, &backend);
  52    if (ret < 0) {
  53        return -errno;
  54    }
  55    return 0;
  56}
  57
  58static void vhost_scsi_clear_endpoint(VHostSCSI *s)
  59{
  60    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
  61    struct vhost_scsi_target backend;
  62    const VhostOps *vhost_ops = s->dev.vhost_ops;
  63
  64    memset(&backend, 0, sizeof(backend));
  65    pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
  66    vhost_ops->vhost_scsi_clear_endpoint(&s->dev, &backend);
  67}
  68
  69static int vhost_scsi_start(VHostSCSI *s)
  70{
  71    int ret, abi_version, i;
  72    VirtIODevice *vdev = VIRTIO_DEVICE(s);
  73    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
  74    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
  75    const VhostOps *vhost_ops = s->dev.vhost_ops;
  76
  77    if (!k->set_guest_notifiers) {
  78        error_report("binding does not support guest notifiers");
  79        return -ENOSYS;
  80    }
  81
  82    ret = vhost_ops->vhost_scsi_get_abi_version(&s->dev, &abi_version);
  83    if (ret < 0) {
  84        return -errno;
  85    }
  86    if (abi_version > VHOST_SCSI_ABI_VERSION) {
  87        error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
  88                     " %d is greater than vhost_scsi userspace supports: %d, please"
  89                     " upgrade your version of QEMU", abi_version,
  90                     VHOST_SCSI_ABI_VERSION);
  91        return -ENOSYS;
  92    }
  93
  94    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
  95    if (ret < 0) {
  96        return ret;
  97    }
  98
  99    s->dev.acked_features = vdev->guest_features;
 100    ret = vhost_dev_start(&s->dev, vdev);
 101    if (ret < 0) {
 102        error_report("Error start vhost dev");
 103        goto err_notifiers;
 104    }
 105
 106    ret = vhost_scsi_set_endpoint(s);
 107    if (ret < 0) {
 108        error_report("Error set vhost-scsi endpoint");
 109        goto err_vhost_stop;
 110    }
 111
 112    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
 113    if (ret < 0) {
 114        error_report("Error binding guest notifier");
 115        goto err_endpoint;
 116    }
 117
 118    /* guest_notifier_mask/pending not used yet, so just unmask
 119     * everything here.  virtio-pci will do the right thing by
 120     * enabling/disabling irqfd.
 121     */
 122    for (i = 0; i < s->dev.nvqs; i++) {
 123        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
 124    }
 125
 126    return ret;
 127
 128err_endpoint:
 129    vhost_scsi_clear_endpoint(s);
 130err_vhost_stop:
 131    vhost_dev_stop(&s->dev, vdev);
 132err_notifiers:
 133    vhost_dev_disable_notifiers(&s->dev, vdev);
 134    return ret;
 135}
 136
 137static void vhost_scsi_stop(VHostSCSI *s)
 138{
 139    VirtIODevice *vdev = VIRTIO_DEVICE(s);
 140    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 141    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 142    int ret = 0;
 143
 144    if (k->set_guest_notifiers) {
 145        ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
 146        if (ret < 0) {
 147                error_report("vhost guest notifier cleanup failed: %d", ret);
 148        }
 149    }
 150    assert(ret >= 0);
 151
 152    vhost_scsi_clear_endpoint(s);
 153    vhost_dev_stop(&s->dev, vdev);
 154    vhost_dev_disable_notifiers(&s->dev, vdev);
 155}
 156
 157static uint64_t vhost_scsi_get_features(VirtIODevice *vdev,
 158                                        uint64_t features,
 159                                        Error **errp)
 160{
 161    VHostSCSI *s = VHOST_SCSI(vdev);
 162
 163    return vhost_get_features(&s->dev, kernel_feature_bits, features);
 164}
 165
 166static void vhost_scsi_set_config(VirtIODevice *vdev,
 167                                  const uint8_t *config)
 168{
 169    VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
 170    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
 171
 172    if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
 173        (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
 174        error_report("vhost-scsi does not support changing the sense data and CDB sizes");
 175        exit(1);
 176    }
 177}
 178
 179static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 180{
 181    VHostSCSI *s = (VHostSCSI *)vdev;
 182    bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 183
 184    if (s->dev.started == start) {
 185        return;
 186    }
 187
 188    if (start) {
 189        int ret;
 190
 191        ret = vhost_scsi_start(s);
 192        if (ret < 0) {
 193            error_report("virtio-scsi: unable to start vhost: %s",
 194                         strerror(-ret));
 195
 196            /* There is no userspace virtio-scsi fallback so exit */
 197            exit(1);
 198        }
 199    } else {
 200        vhost_scsi_stop(s);
 201    }
 202}
 203
 204static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 205{
 206}
 207
 208static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 209{
 210    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 211    VHostSCSI *s = VHOST_SCSI(dev);
 212    Error *err = NULL;
 213    int vhostfd = -1;
 214    int ret;
 215
 216    if (!vs->conf.wwpn) {
 217        error_setg(errp, "vhost-scsi: missing wwpn");
 218        return;
 219    }
 220
 221    if (vs->conf.vhostfd) {
 222        vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp);
 223        if (vhostfd == -1) {
 224            error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
 225            return;
 226        }
 227    } else {
 228        vhostfd = open("/dev/vhost-scsi", O_RDWR);
 229        if (vhostfd < 0) {
 230            error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 231                       strerror(errno));
 232            return;
 233        }
 234    }
 235
 236    virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
 237                               vhost_dummy_handle_output,
 238                               vhost_dummy_handle_output);
 239    if (err != NULL) {
 240        error_propagate(errp, err);
 241        close(vhostfd);
 242        return;
 243    }
 244
 245    s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 246    s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
 247    s->dev.vq_index = 0;
 248    s->dev.backend_features = 0;
 249
 250    ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
 251                         VHOST_BACKEND_TYPE_KERNEL, 0);
 252    if (ret < 0) {
 253        error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 254                   strerror(-ret));
 255        return;
 256    }
 257
 258    /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 259    s->channel = 0;
 260    s->lun = 0;
 261    /* Note: we can also get the minimum tpgt from kernel */
 262    s->target = vs->conf.boot_tpgt;
 263
 264    error_setg(&s->migration_blocker,
 265            "vhost-scsi does not support migration");
 266    migrate_add_blocker(s->migration_blocker);
 267}
 268
 269static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 270{
 271    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 272    VHostSCSI *s = VHOST_SCSI(dev);
 273
 274    migrate_del_blocker(s->migration_blocker);
 275    error_free(s->migration_blocker);
 276
 277    /* This will stop vhost backend. */
 278    vhost_scsi_set_status(vdev, 0);
 279
 280    vhost_dev_cleanup(&s->dev);
 281    g_free(s->dev.vqs);
 282
 283    virtio_scsi_common_unrealize(dev, errp);
 284}
 285
 286/*
 287 * Implementation of an interface to adjust firmware path
 288 * for the bootindex property handling.
 289 */
 290static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
 291                                        DeviceState *dev)
 292{
 293    VHostSCSI *s = VHOST_SCSI(dev);
 294    /* format: channel@channel/vhost-scsi@target,lun */
 295    return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel,
 296                           qdev_fw_name(dev), s->target, s->lun);
 297}
 298
 299static Property vhost_scsi_properties[] = {
 300    DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd),
 301    DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn),
 302    DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0),
 303    DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1),
 304    DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors,
 305                                                 0xFFFF),
 306    DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun,
 307                                                 128),
 308    DEFINE_PROP_END_OF_LIST(),
 309};
 310
 311static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 312{
 313    DeviceClass *dc = DEVICE_CLASS(klass);
 314    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 315    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 316
 317    dc->props = vhost_scsi_properties;
 318    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 319    vdc->realize = vhost_scsi_realize;
 320    vdc->unrealize = vhost_scsi_unrealize;
 321    vdc->get_features = vhost_scsi_get_features;
 322    vdc->set_config = vhost_scsi_set_config;
 323    vdc->set_status = vhost_scsi_set_status;
 324    fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
 325}
 326
 327static void vhost_scsi_instance_init(Object *obj)
 328{
 329    VHostSCSI *dev = VHOST_SCSI(obj);
 330
 331    device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
 332                                  DEVICE(dev), NULL);
 333}
 334
 335static const TypeInfo vhost_scsi_info = {
 336    .name = TYPE_VHOST_SCSI,
 337    .parent = TYPE_VIRTIO_SCSI_COMMON,
 338    .instance_size = sizeof(VHostSCSI),
 339    .class_init = vhost_scsi_class_init,
 340    .instance_init = vhost_scsi_instance_init,
 341    .interfaces = (InterfaceInfo[]) {
 342        { TYPE_FW_PATH_PROVIDER },
 343        { }
 344    },
 345};
 346
 347static void virtio_register_types(void)
 348{
 349    type_register_static(&vhost_scsi_info);
 350}
 351
 352type_init(virtio_register_types)
 353