1 /* 2 * Virtio vsock device 3 * 4 * Copyright 2015 Red Hat, Inc. 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * (at your option) any later version. See the COPYING file in the 11 * top-level directory. 12 */ 13 14 #include <sys/ioctl.h> 15 #include "qemu/osdep.h" 16 #include "standard-headers/linux/virtio_vsock.h" 17 #include "qapi/error.h" 18 #include "hw/virtio/virtio-bus.h" 19 #include "hw/virtio/virtio-access.h" 20 #include "migration/migration.h" 21 #include "qemu/error-report.h" 22 #include "hw/virtio/vhost-vsock.h" 23 #include "qemu/iov.h" 24 #include "monitor/monitor.h" 25 26 enum { 27 VHOST_VSOCK_SAVEVM_VERSION = 0, 28 29 VHOST_VSOCK_QUEUE_SIZE = 128, 30 }; 31 32 static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config) 33 { 34 VHostVSock *vsock = VHOST_VSOCK(vdev); 35 struct virtio_vsock_config vsockcfg = {}; 36 37 virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid); 38 memcpy(config, &vsockcfg, sizeof(vsockcfg)); 39 } 40 41 static int vhost_vsock_set_guest_cid(VHostVSock *vsock) 42 { 43 const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops; 44 int ret; 45 46 if (!vhost_ops->vhost_vsock_set_guest_cid) { 47 return -ENOSYS; 48 } 49 50 ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev, 51 vsock->conf.guest_cid); 52 if (ret < 0) { 53 return -errno; 54 } 55 return 0; 56 } 57 58 static int vhost_vsock_set_running(VHostVSock *vsock, int start) 59 { 60 const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops; 61 int ret; 62 63 if (!vhost_ops->vhost_vsock_set_running) { 64 return -ENOSYS; 65 } 66 67 ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start); 68 if (ret < 0) { 69 return -errno; 70 } 71 return 0; 72 } 73 74 static void vhost_vsock_start(VirtIODevice *vdev) 75 { 76 VHostVSock *vsock = VHOST_VSOCK(vdev); 77 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 78 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 79 int ret; 80 int i; 81 82 if (!k->set_guest_notifiers) { 83 error_report("binding does not support guest notifiers"); 84 return; 85 } 86 87 ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev); 88 if (ret < 0) { 89 error_report("Error enabling host notifiers: %d", -ret); 90 return; 91 } 92 93 ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true); 94 if (ret < 0) { 95 error_report("Error binding guest notifier: %d", -ret); 96 goto err_host_notifiers; 97 } 98 99 vsock->vhost_dev.acked_features = vdev->guest_features; 100 ret = vhost_dev_start(&vsock->vhost_dev, vdev); 101 if (ret < 0) { 102 error_report("Error starting vhost: %d", -ret); 103 goto err_guest_notifiers; 104 } 105 106 ret = vhost_vsock_set_running(vsock, 1); 107 if (ret < 0) { 108 error_report("Error starting vhost vsock: %d", -ret); 109 goto err_dev_start; 110 } 111 112 /* guest_notifier_mask/pending not used yet, so just unmask 113 * everything here. virtio-pci will do the right thing by 114 * enabling/disabling irqfd. 115 */ 116 for (i = 0; i < vsock->vhost_dev.nvqs; i++) { 117 vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false); 118 } 119 120 return; 121 122 err_dev_start: 123 vhost_dev_stop(&vsock->vhost_dev, vdev); 124 err_guest_notifiers: 125 k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false); 126 err_host_notifiers: 127 vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev); 128 } 129 130 static void vhost_vsock_stop(VirtIODevice *vdev) 131 { 132 VHostVSock *vsock = VHOST_VSOCK(vdev); 133 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 134 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 135 int ret; 136 137 if (!k->set_guest_notifiers) { 138 return; 139 } 140 141 ret = vhost_vsock_set_running(vsock, 0); 142 if (ret < 0) { 143 error_report("vhost vsock set running failed: %d", ret); 144 return; 145 } 146 147 vhost_dev_stop(&vsock->vhost_dev, vdev); 148 149 ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false); 150 if (ret < 0) { 151 error_report("vhost guest notifier cleanup failed: %d", ret); 152 return; 153 } 154 155 vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev); 156 } 157 158 static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status) 159 { 160 VHostVSock *vsock = VHOST_VSOCK(vdev); 161 bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; 162 163 if (!vdev->vm_running) { 164 should_start = false; 165 } 166 167 if (vsock->vhost_dev.started == should_start) { 168 return; 169 } 170 171 if (should_start) { 172 vhost_vsock_start(vdev); 173 } else { 174 vhost_vsock_stop(vdev); 175 } 176 } 177 178 static uint64_t vhost_vsock_get_features(VirtIODevice *vdev, 179 uint64_t requested_features, 180 Error **errp) 181 { 182 /* No feature bits used yet */ 183 return requested_features; 184 } 185 186 static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq) 187 { 188 /* Do nothing */ 189 } 190 191 static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx, 192 bool mask) 193 { 194 VHostVSock *vsock = VHOST_VSOCK(vdev); 195 196 vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask); 197 } 198 199 static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx) 200 { 201 VHostVSock *vsock = VHOST_VSOCK(vdev); 202 203 return vhost_virtqueue_pending(&vsock->vhost_dev, idx); 204 } 205 206 static void vhost_vsock_send_transport_reset(VHostVSock *vsock) 207 { 208 VirtQueueElement *elem; 209 VirtQueue *vq = vsock->event_vq; 210 struct virtio_vsock_event event = { 211 .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET), 212 }; 213 214 elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); 215 if (!elem) { 216 error_report("vhost-vsock missed transport reset event"); 217 return; 218 } 219 220 if (elem->out_num) { 221 error_report("invalid vhost-vsock event virtqueue element with " 222 "out buffers"); 223 goto out; 224 } 225 226 if (iov_from_buf(elem->in_sg, elem->in_num, 0, 227 &event, sizeof(event)) != sizeof(event)) { 228 error_report("vhost-vsock event virtqueue element is too short"); 229 goto out; 230 } 231 232 virtqueue_push(vq, elem, sizeof(event)); 233 virtio_notify(VIRTIO_DEVICE(vsock), vq); 234 235 out: 236 g_free(elem); 237 } 238 239 static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock) 240 { 241 if (!vsock->post_load_timer) { 242 return; 243 } 244 245 timer_del(vsock->post_load_timer); 246 timer_free(vsock->post_load_timer); 247 vsock->post_load_timer = NULL; 248 } 249 250 static void vhost_vsock_post_load_timer_cb(void *opaque) 251 { 252 VHostVSock *vsock = opaque; 253 254 vhost_vsock_post_load_timer_cleanup(vsock); 255 vhost_vsock_send_transport_reset(vsock); 256 } 257 258 static void vhost_vsock_pre_save(void *opaque) 259 { 260 VHostVSock *vsock = opaque; 261 262 /* At this point, backend must be stopped, otherwise 263 * it might keep writing to memory. */ 264 assert(!vsock->vhost_dev.started); 265 } 266 267 static int vhost_vsock_post_load(void *opaque, int version_id) 268 { 269 VHostVSock *vsock = opaque; 270 VirtIODevice *vdev = VIRTIO_DEVICE(vsock); 271 272 if (virtio_queue_get_addr(vdev, 2)) { 273 /* Defer transport reset event to a vm clock timer so that virtqueue 274 * changes happen after migration has completed. 275 */ 276 assert(!vsock->post_load_timer); 277 vsock->post_load_timer = 278 timer_new_ns(QEMU_CLOCK_VIRTUAL, 279 vhost_vsock_post_load_timer_cb, 280 vsock); 281 timer_mod(vsock->post_load_timer, 1); 282 } 283 return 0; 284 } 285 286 static const VMStateDescription vmstate_virtio_vhost_vsock = { 287 .name = "virtio-vhost_vsock", 288 .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION, 289 .version_id = VHOST_VSOCK_SAVEVM_VERSION, 290 .fields = (VMStateField[]) { 291 VMSTATE_VIRTIO_DEVICE, 292 VMSTATE_END_OF_LIST() 293 }, 294 .pre_save = vhost_vsock_pre_save, 295 .post_load = vhost_vsock_post_load, 296 }; 297 298 static void vhost_vsock_device_realize(DeviceState *dev, Error **errp) 299 { 300 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 301 VHostVSock *vsock = VHOST_VSOCK(dev); 302 int vhostfd; 303 int ret; 304 305 /* Refuse to use reserved CID numbers */ 306 if (vsock->conf.guest_cid <= 2) { 307 error_setg(errp, "guest-cid property must be greater than 2"); 308 return; 309 } 310 311 if (vsock->conf.guest_cid > UINT32_MAX) { 312 error_setg(errp, "guest-cid property must be a 32-bit number"); 313 return; 314 } 315 316 if (vsock->conf.vhostfd) { 317 vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp); 318 if (vhostfd == -1) { 319 error_prepend(errp, "vhost-vsock: unable to parse vhostfd: "); 320 return; 321 } 322 } else { 323 vhostfd = open("/dev/vhost-vsock", O_RDWR); 324 if (vhostfd < 0) { 325 error_setg_errno(errp, -errno, 326 "vhost-vsock: failed to open vhost device"); 327 return; 328 } 329 } 330 331 virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK, 332 sizeof(struct virtio_vsock_config)); 333 334 /* Receive and transmit queues belong to vhost */ 335 virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output); 336 virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output); 337 338 /* The event queue belongs to QEMU */ 339 vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, 340 vhost_vsock_handle_output); 341 342 vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs); 343 vsock->vhost_dev.vqs = vsock->vhost_vqs; 344 ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd, 345 VHOST_BACKEND_TYPE_KERNEL, 0); 346 if (ret < 0) { 347 error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed"); 348 goto err_virtio; 349 } 350 351 ret = vhost_vsock_set_guest_cid(vsock); 352 if (ret < 0) { 353 error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid"); 354 goto err_vhost_dev; 355 } 356 357 vsock->post_load_timer = NULL; 358 return; 359 360 err_vhost_dev: 361 vhost_dev_cleanup(&vsock->vhost_dev); 362 err_virtio: 363 virtio_cleanup(vdev); 364 close(vhostfd); 365 return; 366 } 367 368 static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp) 369 { 370 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 371 VHostVSock *vsock = VHOST_VSOCK(dev); 372 373 vhost_vsock_post_load_timer_cleanup(vsock); 374 375 /* This will stop vhost backend if appropriate. */ 376 vhost_vsock_set_status(vdev, 0); 377 378 vhost_dev_cleanup(&vsock->vhost_dev); 379 virtio_cleanup(vdev); 380 } 381 382 static Property vhost_vsock_properties[] = { 383 DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0), 384 DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd), 385 DEFINE_PROP_END_OF_LIST(), 386 }; 387 388 static void vhost_vsock_class_init(ObjectClass *klass, void *data) 389 { 390 DeviceClass *dc = DEVICE_CLASS(klass); 391 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 392 393 dc->props = vhost_vsock_properties; 394 dc->vmsd = &vmstate_virtio_vhost_vsock; 395 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 396 vdc->realize = vhost_vsock_device_realize; 397 vdc->unrealize = vhost_vsock_device_unrealize; 398 vdc->get_features = vhost_vsock_get_features; 399 vdc->get_config = vhost_vsock_get_config; 400 vdc->set_status = vhost_vsock_set_status; 401 vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask; 402 vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending; 403 } 404 405 static const TypeInfo vhost_vsock_info = { 406 .name = TYPE_VHOST_VSOCK, 407 .parent = TYPE_VIRTIO_DEVICE, 408 .instance_size = sizeof(VHostVSock), 409 .class_init = vhost_vsock_class_init, 410 }; 411 412 static void vhost_vsock_register_types(void) 413 { 414 type_register_static(&vhost_vsock_info); 415 } 416 417 type_init(vhost_vsock_register_types) 418