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     Error *local_err = NULL;
  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, &local_err);
  93     if (ret < 0) {
  94         error_reportf_err(local_err, "Error starting vhost-scsi: ");
  95         return ret;
  96     }
  97
  98     ret = vhost_scsi_set_endpoint(s);
  99     if (ret < 0) {
 100         error_report("Error setting vhost-scsi endpoint");
 101         vhost_scsi_common_stop(vsc);
 102     }
 103
 104     return ret;
 105 }
 106
 107 static void vhost_scsi_stop(VHostSCSI *s)
 108 {
 109     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 110
 111     vhost_scsi_clear_endpoint(s);
 112     vhost_scsi_common_stop(vsc);
 113 }
 114
 115 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 116 {
 117     VHostSCSI *s = VHOST_SCSI(vdev);
 118     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 119     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);
 120
 121     if (!vdev->vm_running) {
 122         start = false;
 123     }
 124
 125     if (vhost_dev_is_started(&vsc->dev) == start) {
 126         return;
 127     }
 128
 129     if (start) {
 130         int ret;
 131
 132         ret = vhost_scsi_start(s);
 133         if (ret < 0) {
 134             error_report("unable to start vhost-scsi: %s", strerror(-ret));
 135             exit(1);
 136         }
 137     } else {
 138         vhost_scsi_stop(s);
 139     }
 140 }
 141
 142 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 143 {
 144 }
 145
 146 static int vhost_scsi_pre_save(void *opaque)
 147 {
 148     VHostSCSICommon *vsc = opaque;
 149
 150     /* At this point, backend must be stopped, otherwise
 151      * it might keep writing to memory. */
 152     assert(!vhost_dev_is_started(&vsc->dev));
 153
 154     return 0;
 155 }
 156
 157 static const VMStateDescription vmstate_virtio_vhost_scsi = {
 158     .name = "virtio-vhost_scsi",
 159     .minimum_version_id = 1,
 160     .version_id = 1,
 161     .fields = (const VMStateField[]) {
 162         VMSTATE_VIRTIO_DEVICE,
 163         VMSTATE_END_OF_LIST()
 164     },
 165     .pre_save = vhost_scsi_pre_save,
 166 };
 167
 168 static int vhost_scsi_set_workers(VHostSCSICommon *vsc, bool per_virtqueue)
 169 {
 170     struct vhost_dev *dev = &vsc->dev;
 171     struct vhost_vring_worker vq_worker;
 172     struct vhost_worker_state worker;
 173     int i, ret;
 174
 175     /* Use default worker */
 176     if (!per_virtqueue || dev->nvqs == VHOST_SCSI_VQ_NUM_FIXED + 1) {
 177         return 0;
 178     }
 179
 180     /*
 181      * ctl/evt share the first worker since it will be rare for them
 182      * to send cmds while IO is running.
 183      */
 184     for (i = VHOST_SCSI_VQ_NUM_FIXED + 1; i < dev->nvqs; i++) {
 185         memset(&worker, 0, sizeof(worker));
 186
 187         ret = dev->vhost_ops->vhost_new_worker(dev, &worker);
 188         if (ret == -ENOTTY) {
 189             /*
 190              * worker ioctls are not implemented so just ignore and
 191              * and continue device setup.
 192              */
 193             warn_report("vhost-scsi: Backend supports a single worker. "
 194                         "Ignoring worker_per_virtqueue=true setting.");
 195             ret = 0;
 196             break;
 197         } else if (ret) {
 198             break;
 199         }
 200
 201         memset(&vq_worker, 0, sizeof(vq_worker));
 202         vq_worker.worker_id = worker.worker_id;
 203         vq_worker.index = i;
 204
 205         ret = dev->vhost_ops->vhost_attach_vring_worker(dev, &vq_worker);
 206         if (ret == -ENOTTY) {
 207             /*
 208              * It's a bug for the kernel to have supported the worker creation
 209              * ioctl but not attach.
 210              */
 211             dev->vhost_ops->vhost_free_worker(dev, &worker);
 212             break;
 213         } else if (ret) {
 214             break;
 215         }
 216     }
 217
 218     return ret;
 219 }
 220
 221 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 222 {
 223     ERRP_GUARD();
 224     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
 225     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 226     Error *err = NULL;
 227     int vhostfd = -1;
 228     int ret;
 229     struct vhost_virtqueue *vqs = NULL;
 230
 231     if (!vs->conf.wwpn) {
 232         error_setg(errp, "vhost-scsi: missing wwpn");
 233         return;
 234     }
 235
 236     if (vs->conf.vhostfd) {
 237         vhostfd = monitor_fd_param(monitor_cur(), vs->conf.vhostfd, errp);
 238         if (vhostfd == -1) {
 239             error_prepend(errp, "vhost-scsi: unable to parse vhostfd: ");
 240             return;
 241         }
 242     } else {
 243         vhostfd = open("/dev/vhost-scsi", O_RDWR);
 244         if (vhostfd < 0) {
 245             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
 246                        strerror(errno));
 247             return;
 248         }
 249     }
 250
 251     virtio_scsi_common_realize(dev,
 252                                vhost_dummy_handle_output,
 253                                vhost_dummy_handle_output,
 254                                vhost_dummy_handle_output,
 255                                &err);
 256     if (err != NULL) {
 257         error_propagate(errp, err);
 258         goto close_fd;
 259     }
 260
 261     if (!vsc->migratable) {
 262         error_setg(&vsc->migration_blocker,
 263                 "vhost-scsi does not support migration in all cases. "
 264                 "When external environment supports it (Orchestrator migrates "
 265                 "target SCSI device state or use shared storage over network), "
 266                 "set 'migratable' property to true to enable migration.");
 267         if (migrate_add_blocker_normal(&vsc->migration_blocker, errp) < 0) {
 268             goto free_virtio;
 269         }
 270     }
 271
 272     vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
 273     vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
 274     vsc->dev.vqs = vqs;
 275     vsc->dev.vq_index = 0;
 276     vsc->dev.backend_features = 0;
 277
 278     ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
 279                          VHOST_BACKEND_TYPE_KERNEL, 0, errp);
 280     if (ret < 0) {
 281         /*
 282          * vhost_dev_init calls vhost_dev_cleanup on error, which closes
 283          * vhostfd, don't double close it.
 284          */
 285         vhostfd = -1;
 286         goto free_vqs;
 287     }
 288
 289     ret = vhost_scsi_set_workers(vsc, vs->conf.worker_per_virtqueue);
 290     if (ret < 0) {
 291         error_setg(errp, "vhost-scsi: vhost worker setup failed: %s",
 292                    strerror(-ret));
 293         goto free_vqs;
 294     }
 295
 296     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
 297     vsc->channel = 0;
 298     vsc->lun = 0;
 299     /* Note: we can also get the minimum tpgt from kernel */
 300     vsc->target = vs->conf.boot_tpgt;
 301
 302     return;
 303
 304  free_vqs:
 305     g_free(vqs);
 306     if (!vsc->migratable) {
 307         migrate_del_blocker(&vsc->migration_blocker);
 308     }
 309  free_virtio:
 310     virtio_scsi_common_unrealize(dev);
 311  close_fd:
 312     if (vhostfd >= 0) {
 313         close(vhostfd);
 314     }
 315     return;
 316 }
 317
 318 static void vhost_scsi_unrealize(DeviceState *dev)
 319 {
 320     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 321     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
 322     struct vhost_virtqueue *vqs = vsc->dev.vqs;
 323
 324     if (!vsc->migratable) {
 325         migrate_del_blocker(&vsc->migration_blocker);
 326     }
 327
 328     /* This will stop vhost backend. */
 329     vhost_scsi_set_status(vdev, 0);
 330
 331     vhost_dev_cleanup(&vsc->dev);
 332     g_free(vqs);
 333
 334     virtio_scsi_common_unrealize(dev);
 335 }
 336
 337 static struct vhost_dev *vhost_scsi_get_vhost(VirtIODevice *vdev)
 338 {
 339     VHostSCSI *s = VHOST_SCSI(vdev);
 340     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
 341     return &vsc->dev;
 342 }
 343
 344 static Property vhost_scsi_properties[] = {
 345     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
 346     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
 347     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
 348     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
 349                        VIRTIO_SCSI_AUTO_NUM_QUEUES),
 350     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
 351                        128),
 352     DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
 353                       true),
 354     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
 355                        0xFFFF),
 356     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
 357     DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
 358                                                  VIRTIO_SCSI_F_T10_PI,
 359                                                  false),
 360     DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false),
 361     DEFINE_PROP_BOOL("worker_per_virtqueue", VirtIOSCSICommon,
 362                      conf.worker_per_virtqueue, false),
 363     DEFINE_PROP_END_OF_LIST(),
 364 };
 365
 366 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 367 {
 368     DeviceClass *dc = DEVICE_CLASS(klass);
 369     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 370     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
 371
 372     device_class_set_props(dc, vhost_scsi_properties);
 373     dc->vmsd = &vmstate_virtio_vhost_scsi;
 374     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 375     vdc->realize = vhost_scsi_realize;
 376     vdc->unrealize = vhost_scsi_unrealize;
 377     vdc->get_features = vhost_scsi_common_get_features;
 378     vdc->set_config = vhost_scsi_common_set_config;
 379     vdc->set_status = vhost_scsi_set_status;
 380     vdc->get_vhost = vhost_scsi_get_vhost;
 381     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 382 }
 383
 384 static void vhost_scsi_instance_init(Object *obj)
 385 {
 386     VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
 387
 388     vsc->feature_bits = kernel_feature_bits;
 389
 390     device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
 391                                   DEVICE(vsc));
 392 }
 393
 394 static const TypeInfo vhost_scsi_info = {
 395     .name = TYPE_VHOST_SCSI,
 396     .parent = TYPE_VHOST_SCSI_COMMON,
 397     .instance_size = sizeof(VHostSCSI),
 398     .class_init = vhost_scsi_class_init,
 399     .instance_init = vhost_scsi_instance_init,
 400     .interfaces = (InterfaceInfo[]) {
 401         { TYPE_FW_PATH_PROVIDER },
 402         { }
 403     },
 404 };
 405
 406 static void virtio_register_types(void)
 407 {
 408     type_register_static(&vhost_scsi_info);
 409 }
 410
 411 type_init(virtio_register_types)