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