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 "qapi/error.h" 19 #include <sys/ioctl.h> 20 #include "qemu/error-report.h" 21 #include "qemu/queue.h" 22 #include "monitor/monitor.h" 23 #include "migration/migration.h" 24 #include "hw/virtio/vhost-scsi.h" 25 #include "hw/virtio/vhost.h" 26 #include "hw/virtio/virtio-scsi.h" 27 #include "hw/virtio/virtio-bus.h" 28 #include "hw/virtio/virtio-access.h" 29 #include "hw/fw-path-provider.h" 30 #include "linux/vhost.h" 31 32 /* Features supported by host kernel. */ 33 static const int kernel_feature_bits[] = { 34 VIRTIO_F_NOTIFY_ON_EMPTY, 35 VIRTIO_RING_F_INDIRECT_DESC, 36 VIRTIO_RING_F_EVENT_IDX, 37 VIRTIO_SCSI_F_HOTPLUG, 38 VHOST_INVALID_FEATURE_BIT 39 }; 40 41 static int vhost_scsi_set_endpoint(VHostSCSI *s) 42 { 43 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); 44 const VhostOps *vhost_ops = s->dev.vhost_ops; 45 struct vhost_scsi_target backend; 46 int ret; 47 48 memset(&backend, 0, sizeof(backend)); 49 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn); 50 ret = vhost_ops->vhost_scsi_set_endpoint(&s->dev, &backend); 51 if (ret < 0) { 52 return -errno; 53 } 54 return 0; 55 } 56 57 static void vhost_scsi_clear_endpoint(VHostSCSI *s) 58 { 59 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); 60 struct vhost_scsi_target backend; 61 const VhostOps *vhost_ops = s->dev.vhost_ops; 62 63 memset(&backend, 0, sizeof(backend)); 64 pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn); 65 vhost_ops->vhost_scsi_clear_endpoint(&s->dev, &backend); 66 } 67 68 static int vhost_scsi_start(VHostSCSI *s) 69 { 70 int ret, abi_version, i; 71 VirtIODevice *vdev = VIRTIO_DEVICE(s); 72 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 73 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 74 const VhostOps *vhost_ops = s->dev.vhost_ops; 75 76 if (!k->set_guest_notifiers) { 77 error_report("binding does not support guest notifiers"); 78 return -ENOSYS; 79 } 80 81 ret = vhost_ops->vhost_scsi_get_abi_version(&s->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, please" 88 " upgrade your version of QEMU", abi_version, 89 VHOST_SCSI_ABI_VERSION); 90 return -ENOSYS; 91 } 92 93 ret = vhost_dev_enable_notifiers(&s->dev, vdev); 94 if (ret < 0) { 95 return ret; 96 } 97 98 s->dev.acked_features = vdev->guest_features; 99 ret = vhost_dev_start(&s->dev, vdev); 100 if (ret < 0) { 101 error_report("Error start vhost dev"); 102 goto err_notifiers; 103 } 104 105 ret = vhost_scsi_set_endpoint(s); 106 if (ret < 0) { 107 error_report("Error set vhost-scsi endpoint"); 108 goto err_vhost_stop; 109 } 110 111 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true); 112 if (ret < 0) { 113 error_report("Error binding guest notifier"); 114 goto err_endpoint; 115 } 116 117 /* guest_notifier_mask/pending not used yet, so just unmask 118 * everything here. virtio-pci will do the right thing by 119 * enabling/disabling irqfd. 120 */ 121 for (i = 0; i < s->dev.nvqs; i++) { 122 vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false); 123 } 124 125 return ret; 126 127 err_endpoint: 128 vhost_scsi_clear_endpoint(s); 129 err_vhost_stop: 130 vhost_dev_stop(&s->dev, vdev); 131 err_notifiers: 132 vhost_dev_disable_notifiers(&s->dev, vdev); 133 return ret; 134 } 135 136 static void vhost_scsi_stop(VHostSCSI *s) 137 { 138 VirtIODevice *vdev = VIRTIO_DEVICE(s); 139 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 140 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 141 int ret = 0; 142 143 if (k->set_guest_notifiers) { 144 ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false); 145 if (ret < 0) { 146 error_report("vhost guest notifier cleanup failed: %d", ret); 147 } 148 } 149 assert(ret >= 0); 150 151 vhost_scsi_clear_endpoint(s); 152 vhost_dev_stop(&s->dev, vdev); 153 vhost_dev_disable_notifiers(&s->dev, vdev); 154 } 155 156 static uint64_t vhost_scsi_get_features(VirtIODevice *vdev, 157 uint64_t features, 158 Error **errp) 159 { 160 VHostSCSI *s = VHOST_SCSI(vdev); 161 162 return vhost_get_features(&s->dev, kernel_feature_bits, features); 163 } 164 165 static void vhost_scsi_set_config(VirtIODevice *vdev, 166 const uint8_t *config) 167 { 168 VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config; 169 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev); 170 171 if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size || 172 (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) { 173 error_report("vhost-scsi does not support changing the sense data and CDB sizes"); 174 exit(1); 175 } 176 } 177 178 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val) 179 { 180 VHostSCSI *s = (VHostSCSI *)vdev; 181 bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK); 182 183 if (s->dev.started == start) { 184 return; 185 } 186 187 if (start) { 188 int ret; 189 190 ret = vhost_scsi_start(s); 191 if (ret < 0) { 192 error_report("virtio-scsi: unable to start vhost: %s", 193 strerror(-ret)); 194 195 /* There is no userspace virtio-scsi fallback so exit */ 196 exit(1); 197 } 198 } else { 199 vhost_scsi_stop(s); 200 } 201 } 202 203 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq) 204 { 205 } 206 207 static void vhost_scsi_realize(DeviceState *dev, Error **errp) 208 { 209 VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev); 210 VHostSCSI *s = VHOST_SCSI(dev); 211 Error *err = NULL; 212 int vhostfd = -1; 213 int ret; 214 215 if (!vs->conf.wwpn) { 216 error_setg(errp, "vhost-scsi: missing wwpn"); 217 return; 218 } 219 220 if (vs->conf.vhostfd) { 221 vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, errp); 222 if (vhostfd == -1) { 223 error_prepend(errp, "vhost-scsi: unable to parse vhostfd: "); 224 return; 225 } 226 } else { 227 vhostfd = open("/dev/vhost-scsi", O_RDWR); 228 if (vhostfd < 0) { 229 error_setg(errp, "vhost-scsi: open vhost char device failed: %s", 230 strerror(errno)); 231 return; 232 } 233 } 234 235 virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output, 236 vhost_dummy_handle_output, 237 vhost_dummy_handle_output); 238 if (err != NULL) { 239 error_propagate(errp, err); 240 close(vhostfd); 241 return; 242 } 243 244 s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; 245 s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs); 246 s->dev.vq_index = 0; 247 s->dev.backend_features = 0; 248 249 ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd, 250 VHOST_BACKEND_TYPE_KERNEL); 251 if (ret < 0) { 252 error_setg(errp, "vhost-scsi: vhost initialization failed: %s", 253 strerror(-ret)); 254 return; 255 } 256 257 /* At present, channel and lun both are 0 for bootable vhost-scsi disk */ 258 s->channel = 0; 259 s->lun = 0; 260 /* Note: we can also get the minimum tpgt from kernel */ 261 s->target = vs->conf.boot_tpgt; 262 263 error_setg(&s->migration_blocker, 264 "vhost-scsi does not support migration"); 265 migrate_add_blocker(s->migration_blocker); 266 } 267 268 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp) 269 { 270 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 271 VHostSCSI *s = VHOST_SCSI(dev); 272 273 migrate_del_blocker(s->migration_blocker); 274 error_free(s->migration_blocker); 275 276 /* This will stop vhost backend. */ 277 vhost_scsi_set_status(vdev, 0); 278 279 vhost_dev_cleanup(&s->dev); 280 g_free(s->dev.vqs); 281 282 virtio_scsi_common_unrealize(dev, errp); 283 } 284 285 /* 286 * Implementation of an interface to adjust firmware path 287 * for the bootindex property handling. 288 */ 289 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus, 290 DeviceState *dev) 291 { 292 VHostSCSI *s = VHOST_SCSI(dev); 293 /* format: channel@channel/vhost-scsi@target,lun */ 294 return g_strdup_printf("/channel@%x/%s@%x,%x", s->channel, 295 qdev_fw_name(dev), s->target, s->lun); 296 } 297 298 static Property vhost_scsi_properties[] = { 299 DEFINE_PROP_STRING("vhostfd", VHostSCSI, parent_obj.conf.vhostfd), 300 DEFINE_PROP_STRING("wwpn", VHostSCSI, parent_obj.conf.wwpn), 301 DEFINE_PROP_UINT32("boot_tpgt", VHostSCSI, parent_obj.conf.boot_tpgt, 0), 302 DEFINE_PROP_UINT32("num_queues", VHostSCSI, parent_obj.conf.num_queues, 1), 303 DEFINE_PROP_UINT32("max_sectors", VHostSCSI, parent_obj.conf.max_sectors, 304 0xFFFF), 305 DEFINE_PROP_UINT32("cmd_per_lun", VHostSCSI, parent_obj.conf.cmd_per_lun, 306 128), 307 DEFINE_PROP_END_OF_LIST(), 308 }; 309 310 static void vhost_scsi_class_init(ObjectClass *klass, void *data) 311 { 312 DeviceClass *dc = DEVICE_CLASS(klass); 313 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 314 FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass); 315 316 dc->props = vhost_scsi_properties; 317 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 318 vdc->realize = vhost_scsi_realize; 319 vdc->unrealize = vhost_scsi_unrealize; 320 vdc->get_features = vhost_scsi_get_features; 321 vdc->set_config = vhost_scsi_set_config; 322 vdc->set_status = vhost_scsi_set_status; 323 fwc->get_dev_path = vhost_scsi_get_fw_dev_path; 324 } 325 326 static void vhost_scsi_instance_init(Object *obj) 327 { 328 VHostSCSI *dev = VHOST_SCSI(obj); 329 330 device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL, 331 DEVICE(dev), NULL); 332 } 333 334 static const TypeInfo vhost_scsi_info = { 335 .name = TYPE_VHOST_SCSI, 336 .parent = TYPE_VIRTIO_SCSI_COMMON, 337 .instance_size = sizeof(VHostSCSI), 338 .class_init = vhost_scsi_class_init, 339 .instance_init = vhost_scsi_instance_init, 340 .interfaces = (InterfaceInfo[]) { 341 { TYPE_FW_PATH_PROVIDER }, 342 { } 343 }, 344 }; 345 346 static void virtio_register_types(void) 347 { 348 type_register_static(&vhost_scsi_info); 349 } 350 351 type_init(virtio_register_types) 352