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 VIRTIO_F_NOTIFICATION_DATA, 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 Error *local_err = NULL; 80 81 ret = vhost_ops->vhost_scsi_get_abi_version(&vsc->dev, &abi_version); 82 if (ret < 0) { 83 return -errno; 84 } 85 if (abi_version > VHOST_SCSI_ABI_VERSION) { 86 error_report("vhost-scsi: The running tcm_vhost kernel abi_version:" 87 " %d is greater than vhost_scsi userspace supports: %d," 88 " please upgrade your version of QEMU", abi_version, 89 VHOST_SCSI_ABI_VERSION); 90 return -ENOSYS; 91 } 92 93 ret = vhost_scsi_common_start(vsc, &local_err); 94 if (ret < 0) { 95 error_reportf_err(local_err, "Error starting vhost-scsi: "); 96 return ret; 97 } 98 99 ret = vhost_scsi_set_endpoint(s); 100 if (ret < 0) { 101 error_report("Error setting vhost-scsi endpoint"); 102 vhost_scsi_common_stop(vsc); 103 } 104 105 return ret; 106 } 107 108 static void vhost_scsi_stop(VHostSCSI *s) 109 { 110 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); 111 112 vhost_scsi_clear_endpoint(s); 113 vhost_scsi_common_stop(vsc); 114 } 115 116 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val) 117 { 118 VHostSCSI *s = VHOST_SCSI(vdev); 119 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); 120 bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK); 121 122 if (!vdev->vm_running) { 123 start = false; 124 } 125 126 if (vhost_dev_is_started(&vsc->dev) == start) { 127 return; 128 } 129 130 if (start) { 131 int ret; 132 133 ret = vhost_scsi_start(s); 134 if (ret < 0) { 135 error_report("unable to start vhost-scsi: %s", strerror(-ret)); 136 exit(1); 137 } 138 } else { 139 vhost_scsi_stop(s); 140 } 141 } 142 143 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq) 144 { 145 } 146 147 static int vhost_scsi_pre_save(void *opaque) 148 { 149 VHostSCSICommon *vsc = opaque; 150 151 /* At this point, backend must be stopped, otherwise 152 * it might keep writing to memory. */ 153 assert(!vhost_dev_is_started(&vsc->dev)); 154 155 return 0; 156 } 157 158 static const VMStateDescription vmstate_virtio_vhost_scsi = { 159 .name = "virtio-vhost_scsi", 160 .minimum_version_id = 1, 161 .version_id = 1, 162 .fields = (const VMStateField[]) { 163 VMSTATE_VIRTIO_DEVICE, 164 VMSTATE_END_OF_LIST() 165 }, 166 .pre_save = vhost_scsi_pre_save, 167 }; 168 169 static int vhost_scsi_set_workers(VHostSCSICommon *vsc, bool per_virtqueue) 170 { 171 struct vhost_dev *dev = &vsc->dev; 172 struct vhost_vring_worker vq_worker; 173 struct vhost_worker_state worker; 174 int i, ret; 175 176 /* Use default worker */ 177 if (!per_virtqueue || dev->nvqs == VHOST_SCSI_VQ_NUM_FIXED + 1) { 178 return 0; 179 } 180 181 /* 182 * ctl/evt share the first worker since it will be rare for them 183 * to send cmds while IO is running. 184 */ 185 for (i = VHOST_SCSI_VQ_NUM_FIXED + 1; i < dev->nvqs; i++) { 186 memset(&worker, 0, sizeof(worker)); 187 188 ret = dev->vhost_ops->vhost_new_worker(dev, &worker); 189 if (ret == -ENOTTY) { 190 /* 191 * worker ioctls are not implemented so just ignore and 192 * and continue device setup. 193 */ 194 warn_report("vhost-scsi: Backend supports a single worker. " 195 "Ignoring worker_per_virtqueue=true setting."); 196 ret = 0; 197 break; 198 } else if (ret) { 199 break; 200 } 201 202 memset(&vq_worker, 0, sizeof(vq_worker)); 203 vq_worker.worker_id = worker.worker_id; 204 vq_worker.index = i; 205 206 ret = dev->vhost_ops->vhost_attach_vring_worker(dev, &vq_worker); 207 if (ret == -ENOTTY) { 208 /* 209 * It's a bug for the kernel to have supported the worker creation 210 * ioctl but not attach. 211 */ 212 dev->vhost_ops->vhost_free_worker(dev, &worker); 213 break; 214 } else if (ret) { 215 break; 216 } 217 } 218 219 return ret; 220 } 221 222 static void vhost_scsi_realize(DeviceState *dev, Error **errp) 223 { 224 ERRP_GUARD(); 225 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev); 226 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev); 227 Error *err = NULL; 228 int vhostfd = -1; 229 int ret; 230 struct vhost_virtqueue *vqs = NULL; 231 232 if (!vs->conf.wwpn) { 233 error_setg(errp, "vhost-scsi: missing wwpn"); 234 return; 235 } 236 237 if (vs->conf.vhostfd) { 238 vhostfd = monitor_fd_param(monitor_cur(), vs->conf.vhostfd, errp); 239 if (vhostfd == -1) { 240 error_prepend(errp, "vhost-scsi: unable to parse vhostfd: "); 241 return; 242 } 243 } else { 244 vhostfd = open("/dev/vhost-scsi", O_RDWR); 245 if (vhostfd < 0) { 246 error_setg(errp, "vhost-scsi: open vhost char device failed: %s", 247 strerror(errno)); 248 return; 249 } 250 } 251 252 virtio_scsi_common_realize(dev, 253 vhost_dummy_handle_output, 254 vhost_dummy_handle_output, 255 vhost_dummy_handle_output, 256 &err); 257 if (err != NULL) { 258 error_propagate(errp, err); 259 goto close_fd; 260 } 261 262 if (!vsc->migratable) { 263 error_setg(&vsc->migration_blocker, 264 "vhost-scsi does not support migration in all cases. " 265 "When external environment supports it (Orchestrator migrates " 266 "target SCSI device state or use shared storage over network), " 267 "set 'migratable' property to true to enable migration."); 268 if (migrate_add_blocker_normal(&vsc->migration_blocker, errp) < 0) { 269 goto free_virtio; 270 } 271 } 272 273 vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; 274 vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs); 275 vsc->dev.vqs = vqs; 276 vsc->dev.vq_index = 0; 277 vsc->dev.backend_features = 0; 278 279 ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd, 280 VHOST_BACKEND_TYPE_KERNEL, 0, errp); 281 if (ret < 0) { 282 /* 283 * vhost_dev_init calls vhost_dev_cleanup on error, which closes 284 * vhostfd, don't double close it. 285 */ 286 vhostfd = -1; 287 goto free_vqs; 288 } 289 290 ret = vhost_scsi_set_workers(vsc, vs->conf.worker_per_virtqueue); 291 if (ret < 0) { 292 error_setg(errp, "vhost-scsi: vhost worker setup failed: %s", 293 strerror(-ret)); 294 goto free_vqs; 295 } 296 297 /* At present, channel and lun both are 0 for bootable vhost-scsi disk */ 298 vsc->channel = 0; 299 vsc->lun = 0; 300 /* Note: we can also get the minimum tpgt from kernel */ 301 vsc->target = vs->conf.boot_tpgt; 302 303 return; 304 305 free_vqs: 306 g_free(vqs); 307 if (!vsc->migratable) { 308 migrate_del_blocker(&vsc->migration_blocker); 309 } 310 free_virtio: 311 virtio_scsi_common_unrealize(dev); 312 close_fd: 313 if (vhostfd >= 0) { 314 close(vhostfd); 315 } 316 return; 317 } 318 319 static void vhost_scsi_unrealize(DeviceState *dev) 320 { 321 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 322 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev); 323 struct vhost_virtqueue *vqs = vsc->dev.vqs; 324 325 if (!vsc->migratable) { 326 migrate_del_blocker(&vsc->migration_blocker); 327 } 328 329 /* This will stop vhost backend. */ 330 vhost_scsi_set_status(vdev, 0); 331 332 vhost_dev_cleanup(&vsc->dev); 333 g_free(vqs); 334 335 virtio_scsi_common_unrealize(dev); 336 } 337 338 static struct vhost_dev *vhost_scsi_get_vhost(VirtIODevice *vdev) 339 { 340 VHostSCSI *s = VHOST_SCSI(vdev); 341 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); 342 return &vsc->dev; 343 } 344 345 static Property vhost_scsi_properties[] = { 346 DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd), 347 DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn), 348 DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0), 349 DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 350 VIRTIO_SCSI_AUTO_NUM_QUEUES), 351 DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size, 352 128), 353 DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust, 354 true), 355 DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors, 356 0xFFFF), 357 DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128), 358 DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features, 359 VIRTIO_SCSI_F_T10_PI, 360 false), 361 DEFINE_PROP_BOOL("migratable", VHostSCSICommon, migratable, false), 362 DEFINE_PROP_BOOL("worker_per_virtqueue", VirtIOSCSICommon, 363 conf.worker_per_virtqueue, false), 364 DEFINE_PROP_END_OF_LIST(), 365 }; 366 367 static void vhost_scsi_class_init(ObjectClass *klass, void *data) 368 { 369 DeviceClass *dc = DEVICE_CLASS(klass); 370 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 371 FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass); 372 373 device_class_set_props(dc, vhost_scsi_properties); 374 dc->vmsd = &vmstate_virtio_vhost_scsi; 375 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 376 vdc->realize = vhost_scsi_realize; 377 vdc->unrealize = vhost_scsi_unrealize; 378 vdc->get_features = vhost_scsi_common_get_features; 379 vdc->set_config = vhost_scsi_common_set_config; 380 vdc->set_status = vhost_scsi_set_status; 381 vdc->get_vhost = vhost_scsi_get_vhost; 382 fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path; 383 } 384 385 static void vhost_scsi_instance_init(Object *obj) 386 { 387 VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj); 388 389 vsc->feature_bits = kernel_feature_bits; 390 391 device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL, 392 DEVICE(vsc)); 393 } 394 395 static const TypeInfo vhost_scsi_info = { 396 .name = TYPE_VHOST_SCSI, 397 .parent = TYPE_VHOST_SCSI_COMMON, 398 .instance_size = sizeof(VHostSCSI), 399 .class_init = vhost_scsi_class_init, 400 .instance_init = vhost_scsi_instance_init, 401 .interfaces = (InterfaceInfo[]) { 402 { TYPE_FW_PATH_PROVIDER }, 403 { } 404 }, 405 }; 406 407 static void virtio_register_types(void) 408 { 409 type_register_static(&vhost_scsi_info); 410 } 411 412 type_init(virtio_register_types) 413