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 "hw/qdev-properties.h"
  32 #include "qemu/cutils.h"
  33 #include "sysemu/sysemu.h"
  34
  35 /* Features supported by host kernel. */
  36 static 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
  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 (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
 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(!vsc->dev.started);
 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
 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         migrate_add_blocker(vsc->migration_blocker, &err);
 211         if (err) {
 212             error_propagate(errp, err);
 213             error_free(vsc->migration_blocker);
 214             goto free_virtio;
 215         }
 216     }
 217
 218     vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 219     vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
 220     vsc->dev.vq_index = 0;
 221     vsc->dev.backend_features = 0;
 222
 223     ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
 224                          VHOST_BACKEND_TYPE_KERNEL, 0);
 225     if (ret < 0) {
 226         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
 227                    strerror(-ret));
 228         goto free_vqs;
 229     }
 230
 231     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 232     vsc->channel = 0;
 233     vsc->lun = 0;
 234     /* Note: we can also get the minimum tpgt from kernel */
 235     vsc->target = vs->conf.boot_tpgt;
 236
 237     return;
 238
 239  free_vqs:
 240     if (!vsc->migratable) {
 241         migrate_del_blocker(vsc->migration_blocker);
 242     }
 243     g_free(vsc->dev.vqs);
 244  free_virtio:
 245     virtio_scsi_common_unrealize(dev);
 246  close_fd:
 247     close(vhostfd);
 248     return;
 249 }
 250
 251 static void vhost_scsi_unrealize(DeviceState *dev)
 252 {
 253     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 254     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 255     struct vhost_virtqueue *vqs = vsc->dev.vqs;
 256
 257     if (!vsc->migratable) {
 258         migrate_del_blocker(vsc->migration_blocker);
 259         error_free(vsc->migration_blocker);
 260     }
 261
 262     /* This will stop vhost backend. */
 263     vhost_scsi_set_status(vdev, 0);
 264
 265     vhost_dev_cleanup(&vsc->dev);
 266     g_free(vqs);
 267
 268     virtio_scsi_common_unrealize(dev);
 269 }
 270
 271 static Property vhost_scsi_properties[] = {
 272     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
 273     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
 274     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
 275     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
 276     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
 277                        128),
 278     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
 279                       true),
 280     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 281                        0xFFFF),
 282     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 283     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 284                                                  VIRTIO_SCSI_F_T10_PI,
 285                                                  false),
 286     DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
 287     DEFINE_PROP_END_OF_LIST(),
 288 };
 289
 290 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 291 {
 292     DeviceClass *dc = DEVICE_CLASS(klass);
 293     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 294     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 295
 296     device_class_set_props(dc, vhost_scsi_properties);
 297     dc->vmsd = &vmstate_virtio_vhost_scsi;
 298     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 299     vdc->realize = vhost_scsi_realize;
 300     vdc->unrealize = vhost_scsi_unrealize;
 301     vdc->get_features = vhost_scsi_common_get_features;
 302     vdc->set_config = vhost_scsi_common_set_config;
 303     vdc->set_status = vhost_scsi_set_status;
 304     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 305 }
 306
 307 static void vhost_scsi_instance_init(Object *obj)
 308 {
 309     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 310
 311     vsc->feature_bits = kernel_feature_bits;
 312
 313     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 314                                   DEVICE(vsc));
 315 }
 316
 317 static const TypeInfo vhost_scsi_info = {
 318     .name = TYPE_VHOST_SCSI,
 319     .parent = TYPE_VHOST_SCSI_COMMON,
 320     .instance_size = sizeof(VHostSCSI),
 321     .class_init = vhost_scsi_class_init,
 322     .instance_init = vhost_scsi_instance_init,
 323     .interfaces = (InterfaceInfo[]) {
 324         { TYPE_FW_PATH_PROVIDER },
 325         { }
 326     },
 327 };
 328
 329 static void virtio_register_types(void)
 330 {
 331     type_register_static(&vhost_scsi_info);
 332 }
 333
 334 type_init(virtio_register_types)