| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * Xenbus code for netif backend |
| 4 | * |
| 5 | * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au> |
| 6 | * Copyright (C) 2005 XenSource Ltd |
| 7 | */ |
| 8 | |
| 9 | #include "common.h" |
| 10 | #include <linux/vmalloc.h> |
| 11 | #include <linux/rtnetlink.h> |
| 12 | |
| 13 | static int connect_data_rings(struct backend_info *be, |
| 14 | struct xenvif_queue *queue); |
| 15 | static void connect(struct backend_info *be); |
| 16 | static int read_xenbus_vif_flags(struct backend_info *be); |
| 17 | static int backend_create_xenvif(struct backend_info *be); |
| 18 | static void unregister_hotplug_status_watch(struct backend_info *be); |
| 19 | static void xen_unregister_watchers(struct xenvif *vif); |
| 20 | static void set_backend_state(struct backend_info *be, |
| 21 | enum xenbus_state state); |
| 22 | |
| 23 | #ifdef CONFIG_DEBUG_FS |
| 24 | struct dentry *xen_netback_dbg_root = NULL; |
| 25 | |
| 26 | static int xenvif_read_io_ring(struct seq_file *m, void *v) |
| 27 | { |
| 28 | struct xenvif_queue *queue = m->private; |
| 29 | struct xen_netif_tx_back_ring *tx_ring = &queue->tx; |
| 30 | struct xen_netif_rx_back_ring *rx_ring = &queue->rx; |
| 31 | struct netdev_queue *dev_queue; |
| 32 | |
| 33 | if (tx_ring->sring) { |
| 34 | struct xen_netif_tx_sring *sring = tx_ring->sring; |
| 35 | |
| 36 | seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id, |
| 37 | tx_ring->nr_ents); |
| 38 | seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n", |
| 39 | sring->req_prod, |
| 40 | sring->req_prod - sring->rsp_prod, |
| 41 | tx_ring->req_cons, |
| 42 | tx_ring->req_cons - sring->rsp_prod, |
| 43 | sring->req_event, |
| 44 | sring->req_event - sring->rsp_prod); |
| 45 | seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n", |
| 46 | sring->rsp_prod, |
| 47 | tx_ring->rsp_prod_pvt, |
| 48 | tx_ring->rsp_prod_pvt - sring->rsp_prod, |
| 49 | sring->rsp_event, |
| 50 | sring->rsp_event - sring->rsp_prod); |
| 51 | seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n", |
| 52 | queue->pending_prod, |
| 53 | queue->pending_cons, |
| 54 | nr_pending_reqs(queue)); |
| 55 | seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n", |
| 56 | queue->dealloc_prod, |
| 57 | queue->dealloc_cons, |
| 58 | queue->dealloc_prod - queue->dealloc_cons); |
| 59 | } |
| 60 | |
| 61 | if (rx_ring->sring) { |
| 62 | struct xen_netif_rx_sring *sring = rx_ring->sring; |
| 63 | |
| 64 | seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents); |
| 65 | seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n", |
| 66 | sring->req_prod, |
| 67 | sring->req_prod - sring->rsp_prod, |
| 68 | rx_ring->req_cons, |
| 69 | rx_ring->req_cons - sring->rsp_prod, |
| 70 | sring->req_event, |
| 71 | sring->req_event - sring->rsp_prod); |
| 72 | seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n", |
| 73 | sring->rsp_prod, |
| 74 | rx_ring->rsp_prod_pvt, |
| 75 | rx_ring->rsp_prod_pvt - sring->rsp_prod, |
| 76 | sring->rsp_event, |
| 77 | sring->rsp_event - sring->rsp_prod); |
| 78 | } |
| 79 | |
| 80 | seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n" |
| 81 | "Credit timer_pending: %d, credit: %lu, usec: %lu\n" |
| 82 | "remaining: %lu, expires: %lu, now: %lu\n", |
| 83 | queue->napi.state, queue->napi.weight, |
| 84 | skb_queue_len(&queue->tx_queue), |
| 85 | timer_pending(&queue->credit_timeout), |
| 86 | queue->credit_bytes, |
| 87 | queue->credit_usec, |
| 88 | queue->remaining_credit, |
| 89 | queue->credit_timeout.expires, |
| 90 | jiffies); |
| 91 | |
| 92 | dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id); |
| 93 | |
| 94 | seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n", |
| 95 | queue->rx_queue_len, queue->rx_queue_max, |
| 96 | skb_queue_len(&queue->rx_queue), |
| 97 | netif_tx_queue_stopped(dev_queue) ? "stopped" : "running"); |
| 98 | |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | #define XENVIF_KICK_STR "kick" |
| 103 | #define BUFFER_SIZE 32 |
| 104 | |
| 105 | static ssize_t |
| 106 | xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count, |
| 107 | loff_t *ppos) |
| 108 | { |
| 109 | struct xenvif_queue *queue = |
| 110 | ((struct seq_file *)filp->private_data)->private; |
| 111 | int len; |
| 112 | char write[BUFFER_SIZE]; |
| 113 | |
| 114 | /* don't allow partial writes and check the length */ |
| 115 | if (*ppos != 0) |
| 116 | return 0; |
| 117 | if (count >= sizeof(write)) |
| 118 | return -ENOSPC; |
| 119 | |
| 120 | len = simple_write_to_buffer(write, |
| 121 | sizeof(write) - 1, |
| 122 | ppos, |
| 123 | buf, |
| 124 | count); |
| 125 | if (len < 0) |
| 126 | return len; |
| 127 | |
| 128 | write[len] = '\0'; |
| 129 | |
| 130 | if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1)) |
| 131 | xenvif_interrupt(0, (void *)queue); |
| 132 | else { |
| 133 | pr_warn("Unknown command to io_ring_q%d. Available: kick\n", |
| 134 | queue->id); |
| 135 | count = -EINVAL; |
| 136 | } |
| 137 | return count; |
| 138 | } |
| 139 | |
| 140 | static int xenvif_io_ring_open(struct inode *inode, struct file *filp) |
| 141 | { |
| 142 | int ret; |
| 143 | void *queue = NULL; |
| 144 | |
| 145 | if (inode->i_private) |
| 146 | queue = inode->i_private; |
| 147 | ret = single_open(filp, xenvif_read_io_ring, queue); |
| 148 | filp->f_mode |= FMODE_PWRITE; |
| 149 | return ret; |
| 150 | } |
| 151 | |
| 152 | static const struct file_operations xenvif_dbg_io_ring_ops_fops = { |
| 153 | .owner = THIS_MODULE, |
| 154 | .open = xenvif_io_ring_open, |
| 155 | .read = seq_read, |
| 156 | .llseek = seq_lseek, |
| 157 | .release = single_release, |
| 158 | .write = xenvif_write_io_ring, |
| 159 | }; |
| 160 | |
| 161 | static int xenvif_ctrl_show(struct seq_file *m, void *v) |
| 162 | { |
| 163 | struct xenvif *vif = m->private; |
| 164 | |
| 165 | xenvif_dump_hash_info(vif, m); |
| 166 | |
| 167 | return 0; |
| 168 | } |
| 169 | DEFINE_SHOW_ATTRIBUTE(xenvif_ctrl); |
| 170 | |
| 171 | static void xenvif_debugfs_addif(struct xenvif *vif) |
| 172 | { |
| 173 | int i; |
| 174 | |
| 175 | vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name, |
| 176 | xen_netback_dbg_root); |
| 177 | for (i = 0; i < vif->num_queues; ++i) { |
| 178 | char filename[sizeof("io_ring_q") + 4]; |
| 179 | |
| 180 | snprintf(filename, sizeof(filename), "io_ring_q%d", i); |
| 181 | debugfs_create_file(filename, 0600, vif->xenvif_dbg_root, |
| 182 | &vif->queues[i], |
| 183 | &xenvif_dbg_io_ring_ops_fops); |
| 184 | } |
| 185 | |
| 186 | if (vif->ctrl_irq) |
| 187 | debugfs_create_file("ctrl", 0400, vif->xenvif_dbg_root, vif, |
| 188 | &xenvif_ctrl_fops); |
| 189 | } |
| 190 | |
| 191 | static void xenvif_debugfs_delif(struct xenvif *vif) |
| 192 | { |
| 193 | debugfs_remove_recursive(vif->xenvif_dbg_root); |
| 194 | vif->xenvif_dbg_root = NULL; |
| 195 | } |
| 196 | #endif /* CONFIG_DEBUG_FS */ |
| 197 | |
| 198 | /* |
| 199 | * Handle the creation of the hotplug script environment. We add the script |
| 200 | * and vif variables to the environment, for the benefit of the vif-* hotplug |
| 201 | * scripts. |
| 202 | */ |
| 203 | static int netback_uevent(const struct xenbus_device *xdev, |
| 204 | struct kobj_uevent_env *env) |
| 205 | { |
| 206 | struct backend_info *be = dev_get_drvdata(&xdev->dev); |
| 207 | |
| 208 | if (!be) |
| 209 | return 0; |
| 210 | |
| 211 | if (add_uevent_var(env, "script=%s", be->hotplug_script)) |
| 212 | return -ENOMEM; |
| 213 | |
| 214 | if (!be->vif) |
| 215 | return 0; |
| 216 | |
| 217 | return add_uevent_var(env, "vif=%s", be->vif->dev->name); |
| 218 | } |
| 219 | |
| 220 | |
| 221 | static int backend_create_xenvif(struct backend_info *be) |
| 222 | { |
| 223 | int err; |
| 224 | long handle; |
| 225 | struct xenbus_device *dev = be->dev; |
| 226 | struct xenvif *vif; |
| 227 | |
| 228 | if (be->vif != NULL) |
| 229 | return 0; |
| 230 | |
| 231 | err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle); |
| 232 | if (err != 1) { |
| 233 | xenbus_dev_fatal(dev, err, "reading handle"); |
| 234 | return (err < 0) ? err : -EINVAL; |
| 235 | } |
| 236 | |
| 237 | vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle); |
| 238 | if (IS_ERR(vif)) { |
| 239 | err = PTR_ERR(vif); |
| 240 | xenbus_dev_fatal(dev, err, "creating interface"); |
| 241 | return err; |
| 242 | } |
| 243 | be->vif = vif; |
| 244 | vif->be = be; |
| 245 | |
| 246 | kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE); |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | static void backend_disconnect(struct backend_info *be) |
| 251 | { |
| 252 | struct xenvif *vif = be->vif; |
| 253 | |
| 254 | if (vif) { |
| 255 | unsigned int num_queues = vif->num_queues; |
| 256 | unsigned int queue_index; |
| 257 | |
| 258 | xen_unregister_watchers(vif); |
| 259 | #ifdef CONFIG_DEBUG_FS |
| 260 | xenvif_debugfs_delif(vif); |
| 261 | #endif /* CONFIG_DEBUG_FS */ |
| 262 | xenvif_disconnect_data(vif); |
| 263 | |
| 264 | /* At this point some of the handlers may still be active |
| 265 | * so we need to have additional synchronization here. |
| 266 | */ |
| 267 | vif->num_queues = 0; |
| 268 | synchronize_net(); |
| 269 | |
| 270 | for (queue_index = 0; queue_index < num_queues; ++queue_index) |
| 271 | xenvif_deinit_queue(&vif->queues[queue_index]); |
| 272 | |
| 273 | vfree(vif->queues); |
| 274 | vif->queues = NULL; |
| 275 | |
| 276 | xenvif_disconnect_ctrl(vif); |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | static void backend_connect(struct backend_info *be) |
| 281 | { |
| 282 | if (be->vif) |
| 283 | connect(be); |
| 284 | } |
| 285 | |
| 286 | static inline void backend_switch_state(struct backend_info *be, |
| 287 | enum xenbus_state state) |
| 288 | { |
| 289 | struct xenbus_device *dev = be->dev; |
| 290 | |
| 291 | pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state)); |
| 292 | be->state = state; |
| 293 | |
| 294 | /* If we are waiting for a hotplug script then defer the |
| 295 | * actual xenbus state change. |
| 296 | */ |
| 297 | if (!be->have_hotplug_status_watch) |
| 298 | xenbus_switch_state(dev, state); |
| 299 | } |
| 300 | |
| 301 | /* Handle backend state transitions: |
| 302 | * |
| 303 | * The backend state starts in Initialising and the following transitions are |
| 304 | * allowed. |
| 305 | * |
| 306 | * Initialising -> InitWait -> Connected |
| 307 | * \ |
| 308 | * \ ^ \ | |
| 309 | * \ | \ | |
| 310 | * \ | \ | |
| 311 | * \ | \ | |
| 312 | * \ | \ | |
| 313 | * \ | \ | |
| 314 | * V | V V |
| 315 | * |
| 316 | * Closed <-> Closing |
| 317 | * |
| 318 | * The state argument specifies the eventual state of the backend and the |
| 319 | * function transitions to that state via the shortest path. |
| 320 | */ |
| 321 | static void set_backend_state(struct backend_info *be, |
| 322 | enum xenbus_state state) |
| 323 | { |
| 324 | while (be->state != state) { |
| 325 | switch (be->state) { |
| 326 | case XenbusStateInitialising: |
| 327 | switch (state) { |
| 328 | case XenbusStateInitWait: |
| 329 | case XenbusStateConnected: |
| 330 | case XenbusStateClosing: |
| 331 | backend_switch_state(be, XenbusStateInitWait); |
| 332 | break; |
| 333 | case XenbusStateClosed: |
| 334 | backend_switch_state(be, XenbusStateClosed); |
| 335 | break; |
| 336 | default: |
| 337 | BUG(); |
| 338 | } |
| 339 | break; |
| 340 | case XenbusStateClosed: |
| 341 | switch (state) { |
| 342 | case XenbusStateInitWait: |
| 343 | case XenbusStateConnected: |
| 344 | backend_switch_state(be, XenbusStateInitWait); |
| 345 | break; |
| 346 | case XenbusStateClosing: |
| 347 | backend_switch_state(be, XenbusStateClosing); |
| 348 | break; |
| 349 | default: |
| 350 | BUG(); |
| 351 | } |
| 352 | break; |
| 353 | case XenbusStateInitWait: |
| 354 | switch (state) { |
| 355 | case XenbusStateConnected: |
| 356 | backend_connect(be); |
| 357 | backend_switch_state(be, XenbusStateConnected); |
| 358 | break; |
| 359 | case XenbusStateClosing: |
| 360 | case XenbusStateClosed: |
| 361 | backend_switch_state(be, XenbusStateClosing); |
| 362 | break; |
| 363 | default: |
| 364 | BUG(); |
| 365 | } |
| 366 | break; |
| 367 | case XenbusStateConnected: |
| 368 | switch (state) { |
| 369 | case XenbusStateInitWait: |
| 370 | case XenbusStateClosing: |
| 371 | case XenbusStateClosed: |
| 372 | backend_disconnect(be); |
| 373 | backend_switch_state(be, XenbusStateClosing); |
| 374 | break; |
| 375 | default: |
| 376 | BUG(); |
| 377 | } |
| 378 | break; |
| 379 | case XenbusStateClosing: |
| 380 | switch (state) { |
| 381 | case XenbusStateInitWait: |
| 382 | case XenbusStateConnected: |
| 383 | case XenbusStateClosed: |
| 384 | backend_switch_state(be, XenbusStateClosed); |
| 385 | break; |
| 386 | default: |
| 387 | BUG(); |
| 388 | } |
| 389 | break; |
| 390 | default: |
| 391 | BUG(); |
| 392 | } |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | static void read_xenbus_frontend_xdp(struct backend_info *be, |
| 397 | struct xenbus_device *dev) |
| 398 | { |
| 399 | struct xenvif *vif = be->vif; |
| 400 | u16 headroom; |
| 401 | int err; |
| 402 | |
| 403 | err = xenbus_scanf(XBT_NIL, dev->otherend, |
| 404 | "xdp-headroom", "%hu", &headroom); |
| 405 | if (err != 1) { |
| 406 | vif->xdp_headroom = 0; |
| 407 | return; |
| 408 | } |
| 409 | if (headroom > XEN_NETIF_MAX_XDP_HEADROOM) |
| 410 | headroom = XEN_NETIF_MAX_XDP_HEADROOM; |
| 411 | vif->xdp_headroom = headroom; |
| 412 | } |
| 413 | |
| 414 | /* |
| 415 | * Callback received when the frontend's state changes. |
| 416 | */ |
| 417 | static void frontend_changed(struct xenbus_device *dev, |
| 418 | enum xenbus_state frontend_state) |
| 419 | { |
| 420 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
| 421 | |
| 422 | pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state)); |
| 423 | |
| 424 | be->frontend_state = frontend_state; |
| 425 | |
| 426 | switch (frontend_state) { |
| 427 | case XenbusStateInitialising: |
| 428 | set_backend_state(be, XenbusStateInitWait); |
| 429 | break; |
| 430 | |
| 431 | case XenbusStateInitialised: |
| 432 | break; |
| 433 | |
| 434 | case XenbusStateConnected: |
| 435 | set_backend_state(be, XenbusStateConnected); |
| 436 | break; |
| 437 | |
| 438 | case XenbusStateReconfiguring: |
| 439 | read_xenbus_frontend_xdp(be, dev); |
| 440 | xenbus_switch_state(dev, XenbusStateReconfigured); |
| 441 | break; |
| 442 | |
| 443 | case XenbusStateClosing: |
| 444 | set_backend_state(be, XenbusStateClosing); |
| 445 | break; |
| 446 | |
| 447 | case XenbusStateClosed: |
| 448 | set_backend_state(be, XenbusStateClosed); |
| 449 | if (xenbus_dev_is_online(dev)) |
| 450 | break; |
| 451 | fallthrough; /* if not online */ |
| 452 | case XenbusStateUnknown: |
| 453 | set_backend_state(be, XenbusStateClosed); |
| 454 | device_unregister(&dev->dev); |
| 455 | break; |
| 456 | |
| 457 | default: |
| 458 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", |
| 459 | frontend_state); |
| 460 | break; |
| 461 | } |
| 462 | } |
| 463 | |
| 464 | |
| 465 | static void xen_net_read_rate(struct xenbus_device *dev, |
| 466 | unsigned long *bytes, unsigned long *usec) |
| 467 | { |
| 468 | char *s, *e; |
| 469 | unsigned long b, u; |
| 470 | char *ratestr; |
| 471 | |
| 472 | /* Default to unlimited bandwidth. */ |
| 473 | *bytes = ~0UL; |
| 474 | *usec = 0; |
| 475 | |
| 476 | ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL); |
| 477 | if (IS_ERR(ratestr)) |
| 478 | return; |
| 479 | |
| 480 | s = ratestr; |
| 481 | b = simple_strtoul(s, &e, 10); |
| 482 | if ((s == e) || (*e != ',')) |
| 483 | goto fail; |
| 484 | |
| 485 | s = e + 1; |
| 486 | u = simple_strtoul(s, &e, 10); |
| 487 | if ((s == e) || (*e != '\0')) |
| 488 | goto fail; |
| 489 | |
| 490 | *bytes = b; |
| 491 | *usec = u; |
| 492 | |
| 493 | kfree(ratestr); |
| 494 | return; |
| 495 | |
| 496 | fail: |
| 497 | pr_warn("Failed to parse network rate limit. Traffic unlimited.\n"); |
| 498 | kfree(ratestr); |
| 499 | } |
| 500 | |
| 501 | static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) |
| 502 | { |
| 503 | char *s, *e, *macstr; |
| 504 | int i; |
| 505 | |
| 506 | macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); |
| 507 | if (IS_ERR(macstr)) |
| 508 | return PTR_ERR(macstr); |
| 509 | |
| 510 | for (i = 0; i < ETH_ALEN; i++) { |
| 511 | mac[i] = simple_strtoul(s, &e, 16); |
| 512 | if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { |
| 513 | kfree(macstr); |
| 514 | return -ENOENT; |
| 515 | } |
| 516 | s = e+1; |
| 517 | } |
| 518 | |
| 519 | kfree(macstr); |
| 520 | return 0; |
| 521 | } |
| 522 | |
| 523 | static void xen_net_rate_changed(struct xenbus_watch *watch, |
| 524 | const char *path, const char *token) |
| 525 | { |
| 526 | struct xenvif *vif = container_of(watch, struct xenvif, credit_watch); |
| 527 | struct xenbus_device *dev = xenvif_to_xenbus_device(vif); |
| 528 | unsigned long credit_bytes; |
| 529 | unsigned long credit_usec; |
| 530 | unsigned int queue_index; |
| 531 | |
| 532 | xen_net_read_rate(dev, &credit_bytes, &credit_usec); |
| 533 | for (queue_index = 0; queue_index < vif->num_queues; queue_index++) { |
| 534 | struct xenvif_queue *queue = &vif->queues[queue_index]; |
| 535 | |
| 536 | queue->credit_bytes = credit_bytes; |
| 537 | queue->credit_usec = credit_usec; |
| 538 | if (!mod_timer_pending(&queue->credit_timeout, jiffies) && |
| 539 | queue->remaining_credit > queue->credit_bytes) { |
| 540 | queue->remaining_credit = queue->credit_bytes; |
| 541 | } |
| 542 | } |
| 543 | } |
| 544 | |
| 545 | static int xen_register_credit_watch(struct xenbus_device *dev, |
| 546 | struct xenvif *vif) |
| 547 | { |
| 548 | int err = 0; |
| 549 | char *node; |
| 550 | unsigned maxlen = strlen(dev->nodename) + sizeof("/rate"); |
| 551 | |
| 552 | if (vif->credit_watch.node) |
| 553 | return -EADDRINUSE; |
| 554 | |
| 555 | node = kmalloc(maxlen, GFP_KERNEL); |
| 556 | if (!node) |
| 557 | return -ENOMEM; |
| 558 | snprintf(node, maxlen, "%s/rate", dev->nodename); |
| 559 | vif->credit_watch.node = node; |
| 560 | vif->credit_watch.will_handle = NULL; |
| 561 | vif->credit_watch.callback = xen_net_rate_changed; |
| 562 | err = register_xenbus_watch(&vif->credit_watch); |
| 563 | if (err) { |
| 564 | pr_err("Failed to set watcher %s\n", vif->credit_watch.node); |
| 565 | kfree(node); |
| 566 | vif->credit_watch.node = NULL; |
| 567 | vif->credit_watch.will_handle = NULL; |
| 568 | vif->credit_watch.callback = NULL; |
| 569 | } |
| 570 | return err; |
| 571 | } |
| 572 | |
| 573 | static void xen_unregister_credit_watch(struct xenvif *vif) |
| 574 | { |
| 575 | if (vif->credit_watch.node) { |
| 576 | unregister_xenbus_watch(&vif->credit_watch); |
| 577 | kfree(vif->credit_watch.node); |
| 578 | vif->credit_watch.node = NULL; |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | static void xen_mcast_ctrl_changed(struct xenbus_watch *watch, |
| 583 | const char *path, const char *token) |
| 584 | { |
| 585 | struct xenvif *vif = container_of(watch, struct xenvif, |
| 586 | mcast_ctrl_watch); |
| 587 | struct xenbus_device *dev = xenvif_to_xenbus_device(vif); |
| 588 | |
| 589 | vif->multicast_control = !!xenbus_read_unsigned(dev->otherend, |
| 590 | "request-multicast-control", 0); |
| 591 | } |
| 592 | |
| 593 | static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, |
| 594 | struct xenvif *vif) |
| 595 | { |
| 596 | int err = 0; |
| 597 | char *node; |
| 598 | unsigned maxlen = strlen(dev->otherend) + |
| 599 | sizeof("/request-multicast-control"); |
| 600 | |
| 601 | if (vif->mcast_ctrl_watch.node) { |
| 602 | pr_err_ratelimited("Watch is already registered\n"); |
| 603 | return -EADDRINUSE; |
| 604 | } |
| 605 | |
| 606 | node = kmalloc(maxlen, GFP_KERNEL); |
| 607 | if (!node) { |
| 608 | pr_err("Failed to allocate memory for watch\n"); |
| 609 | return -ENOMEM; |
| 610 | } |
| 611 | snprintf(node, maxlen, "%s/request-multicast-control", |
| 612 | dev->otherend); |
| 613 | vif->mcast_ctrl_watch.node = node; |
| 614 | vif->mcast_ctrl_watch.will_handle = NULL; |
| 615 | vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed; |
| 616 | err = register_xenbus_watch(&vif->mcast_ctrl_watch); |
| 617 | if (err) { |
| 618 | pr_err("Failed to set watcher %s\n", |
| 619 | vif->mcast_ctrl_watch.node); |
| 620 | kfree(node); |
| 621 | vif->mcast_ctrl_watch.node = NULL; |
| 622 | vif->mcast_ctrl_watch.will_handle = NULL; |
| 623 | vif->mcast_ctrl_watch.callback = NULL; |
| 624 | } |
| 625 | return err; |
| 626 | } |
| 627 | |
| 628 | static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif) |
| 629 | { |
| 630 | if (vif->mcast_ctrl_watch.node) { |
| 631 | unregister_xenbus_watch(&vif->mcast_ctrl_watch); |
| 632 | kfree(vif->mcast_ctrl_watch.node); |
| 633 | vif->mcast_ctrl_watch.node = NULL; |
| 634 | } |
| 635 | } |
| 636 | |
| 637 | static void xen_register_watchers(struct xenbus_device *dev, |
| 638 | struct xenvif *vif) |
| 639 | { |
| 640 | xen_register_credit_watch(dev, vif); |
| 641 | xen_register_mcast_ctrl_watch(dev, vif); |
| 642 | } |
| 643 | |
| 644 | static void xen_unregister_watchers(struct xenvif *vif) |
| 645 | { |
| 646 | xen_unregister_mcast_ctrl_watch(vif); |
| 647 | xen_unregister_credit_watch(vif); |
| 648 | } |
| 649 | |
| 650 | static void unregister_hotplug_status_watch(struct backend_info *be) |
| 651 | { |
| 652 | if (be->have_hotplug_status_watch) { |
| 653 | unregister_xenbus_watch(&be->hotplug_status_watch); |
| 654 | kfree(be->hotplug_status_watch.node); |
| 655 | } |
| 656 | be->have_hotplug_status_watch = 0; |
| 657 | } |
| 658 | |
| 659 | static void hotplug_status_changed(struct xenbus_watch *watch, |
| 660 | const char *path, |
| 661 | const char *token) |
| 662 | { |
| 663 | struct backend_info *be = container_of(watch, |
| 664 | struct backend_info, |
| 665 | hotplug_status_watch); |
| 666 | char *str; |
| 667 | unsigned int len; |
| 668 | |
| 669 | str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len); |
| 670 | if (IS_ERR(str)) |
| 671 | return; |
| 672 | if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) { |
| 673 | /* Complete any pending state change */ |
| 674 | xenbus_switch_state(be->dev, be->state); |
| 675 | |
| 676 | /* Not interested in this watch anymore. */ |
| 677 | unregister_hotplug_status_watch(be); |
| 678 | } |
| 679 | kfree(str); |
| 680 | } |
| 681 | |
| 682 | static int connect_ctrl_ring(struct backend_info *be) |
| 683 | { |
| 684 | struct xenbus_device *dev = be->dev; |
| 685 | struct xenvif *vif = be->vif; |
| 686 | unsigned int val; |
| 687 | grant_ref_t ring_ref; |
| 688 | unsigned int evtchn; |
| 689 | int err; |
| 690 | |
| 691 | err = xenbus_scanf(XBT_NIL, dev->otherend, |
| 692 | "ctrl-ring-ref", "%u", &val); |
| 693 | if (err < 0) |
| 694 | goto done; /* The frontend does not have a control ring */ |
| 695 | |
| 696 | ring_ref = val; |
| 697 | |
| 698 | err = xenbus_scanf(XBT_NIL, dev->otherend, |
| 699 | "event-channel-ctrl", "%u", &val); |
| 700 | if (err < 0) { |
| 701 | xenbus_dev_fatal(dev, err, |
| 702 | "reading %s/event-channel-ctrl", |
| 703 | dev->otherend); |
| 704 | goto fail; |
| 705 | } |
| 706 | |
| 707 | evtchn = val; |
| 708 | |
| 709 | err = xenvif_connect_ctrl(vif, ring_ref, evtchn); |
| 710 | if (err) { |
| 711 | xenbus_dev_fatal(dev, err, |
| 712 | "mapping shared-frame %u port %u", |
| 713 | ring_ref, evtchn); |
| 714 | goto fail; |
| 715 | } |
| 716 | |
| 717 | done: |
| 718 | return 0; |
| 719 | |
| 720 | fail: |
| 721 | return err; |
| 722 | } |
| 723 | |
| 724 | static void connect(struct backend_info *be) |
| 725 | { |
| 726 | int err; |
| 727 | struct xenbus_device *dev = be->dev; |
| 728 | unsigned long credit_bytes, credit_usec; |
| 729 | unsigned int queue_index; |
| 730 | unsigned int requested_num_queues; |
| 731 | struct xenvif_queue *queue; |
| 732 | |
| 733 | /* Check whether the frontend requested multiple queues |
| 734 | * and read the number requested. |
| 735 | */ |
| 736 | requested_num_queues = xenbus_read_unsigned(dev->otherend, |
| 737 | "multi-queue-num-queues", 1); |
| 738 | if (requested_num_queues > xenvif_max_queues) { |
| 739 | /* buggy or malicious guest */ |
| 740 | xenbus_dev_fatal(dev, -EINVAL, |
| 741 | "guest requested %u queues, exceeding the maximum of %u.", |
| 742 | requested_num_queues, xenvif_max_queues); |
| 743 | return; |
| 744 | } |
| 745 | |
| 746 | err = xen_net_read_mac(dev, be->vif->fe_dev_addr); |
| 747 | if (err) { |
| 748 | xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); |
| 749 | return; |
| 750 | } |
| 751 | |
| 752 | xen_net_read_rate(dev, &credit_bytes, &credit_usec); |
| 753 | xen_unregister_watchers(be->vif); |
| 754 | xen_register_watchers(dev, be->vif); |
| 755 | read_xenbus_vif_flags(be); |
| 756 | |
| 757 | err = connect_ctrl_ring(be); |
| 758 | if (err) { |
| 759 | xenbus_dev_fatal(dev, err, "connecting control ring"); |
| 760 | return; |
| 761 | } |
| 762 | |
| 763 | /* Use the number of queues requested by the frontend */ |
| 764 | be->vif->queues = vzalloc(array_size(requested_num_queues, |
| 765 | sizeof(struct xenvif_queue))); |
| 766 | if (!be->vif->queues) { |
| 767 | xenbus_dev_fatal(dev, -ENOMEM, |
| 768 | "allocating queues"); |
| 769 | return; |
| 770 | } |
| 771 | |
| 772 | be->vif->num_queues = requested_num_queues; |
| 773 | be->vif->stalled_queues = requested_num_queues; |
| 774 | |
| 775 | for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) { |
| 776 | queue = &be->vif->queues[queue_index]; |
| 777 | queue->vif = be->vif; |
| 778 | queue->id = queue_index; |
| 779 | snprintf(queue->name, sizeof(queue->name), "%s-q%u", |
| 780 | be->vif->dev->name, queue->id); |
| 781 | |
| 782 | err = xenvif_init_queue(queue); |
| 783 | if (err) { |
| 784 | /* xenvif_init_queue() cleans up after itself on |
| 785 | * failure, but we need to clean up any previously |
| 786 | * initialised queues. Set num_queues to i so that |
| 787 | * earlier queues can be destroyed using the regular |
| 788 | * disconnect logic. |
| 789 | */ |
| 790 | be->vif->num_queues = queue_index; |
| 791 | goto err; |
| 792 | } |
| 793 | |
| 794 | queue->credit_bytes = credit_bytes; |
| 795 | queue->remaining_credit = credit_bytes; |
| 796 | queue->credit_usec = credit_usec; |
| 797 | |
| 798 | err = connect_data_rings(be, queue); |
| 799 | if (err) { |
| 800 | /* connect_data_rings() cleans up after itself on |
| 801 | * failure, but we need to clean up after |
| 802 | * xenvif_init_queue() here, and also clean up any |
| 803 | * previously initialised queues. |
| 804 | */ |
| 805 | xenvif_deinit_queue(queue); |
| 806 | be->vif->num_queues = queue_index; |
| 807 | goto err; |
| 808 | } |
| 809 | } |
| 810 | |
| 811 | #ifdef CONFIG_DEBUG_FS |
| 812 | xenvif_debugfs_addif(be->vif); |
| 813 | #endif /* CONFIG_DEBUG_FS */ |
| 814 | |
| 815 | /* Initialisation completed, tell core driver the number of |
| 816 | * active queues. |
| 817 | */ |
| 818 | rtnl_lock(); |
| 819 | netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues); |
| 820 | netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues); |
| 821 | rtnl_unlock(); |
| 822 | |
| 823 | xenvif_carrier_on(be->vif); |
| 824 | |
| 825 | unregister_hotplug_status_watch(be); |
| 826 | err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL, |
| 827 | hotplug_status_changed, |
| 828 | "%s/%s", dev->nodename, "hotplug-status"); |
| 829 | if (!err) |
| 830 | be->have_hotplug_status_watch = 1; |
| 831 | |
| 832 | netif_tx_wake_all_queues(be->vif->dev); |
| 833 | |
| 834 | return; |
| 835 | |
| 836 | err: |
| 837 | if (be->vif->num_queues > 0) |
| 838 | xenvif_disconnect_data(be->vif); /* Clean up existing queues */ |
| 839 | for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index) |
| 840 | xenvif_deinit_queue(&be->vif->queues[queue_index]); |
| 841 | vfree(be->vif->queues); |
| 842 | be->vif->queues = NULL; |
| 843 | be->vif->num_queues = 0; |
| 844 | xenvif_disconnect_ctrl(be->vif); |
| 845 | return; |
| 846 | } |
| 847 | |
| 848 | |
| 849 | static int connect_data_rings(struct backend_info *be, |
| 850 | struct xenvif_queue *queue) |
| 851 | { |
| 852 | struct xenbus_device *dev = be->dev; |
| 853 | unsigned int num_queues = queue->vif->num_queues; |
| 854 | unsigned long tx_ring_ref, rx_ring_ref; |
| 855 | unsigned int tx_evtchn, rx_evtchn; |
| 856 | int err; |
| 857 | char *xspath; |
| 858 | size_t xspathsize; |
| 859 | const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */ |
| 860 | |
| 861 | /* If the frontend requested 1 queue, or we have fallen back |
| 862 | * to single queue due to lack of frontend support for multi- |
| 863 | * queue, expect the remaining XenStore keys in the toplevel |
| 864 | * directory. Otherwise, expect them in a subdirectory called |
| 865 | * queue-N. |
| 866 | */ |
| 867 | if (num_queues == 1) { |
| 868 | xspath = kstrdup(dev->otherend, GFP_KERNEL); |
| 869 | if (!xspath) { |
| 870 | xenbus_dev_fatal(dev, -ENOMEM, |
| 871 | "reading ring references"); |
| 872 | return -ENOMEM; |
| 873 | } |
| 874 | } else { |
| 875 | xspathsize = strlen(dev->otherend) + xenstore_path_ext_size; |
| 876 | xspath = kzalloc(xspathsize, GFP_KERNEL); |
| 877 | if (!xspath) { |
| 878 | xenbus_dev_fatal(dev, -ENOMEM, |
| 879 | "reading ring references"); |
| 880 | return -ENOMEM; |
| 881 | } |
| 882 | snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend, |
| 883 | queue->id); |
| 884 | } |
| 885 | |
| 886 | err = xenbus_gather(XBT_NIL, xspath, |
| 887 | "tx-ring-ref", "%lu", &tx_ring_ref, |
| 888 | "rx-ring-ref", "%lu", &rx_ring_ref, NULL); |
| 889 | if (err) { |
| 890 | xenbus_dev_fatal(dev, err, |
| 891 | "reading %s/ring-ref", |
| 892 | xspath); |
| 893 | goto err; |
| 894 | } |
| 895 | |
| 896 | /* Try split event channels first, then single event channel. */ |
| 897 | err = xenbus_gather(XBT_NIL, xspath, |
| 898 | "event-channel-tx", "%u", &tx_evtchn, |
| 899 | "event-channel-rx", "%u", &rx_evtchn, NULL); |
| 900 | if (err < 0) { |
| 901 | err = xenbus_scanf(XBT_NIL, xspath, |
| 902 | "event-channel", "%u", &tx_evtchn); |
| 903 | if (err < 0) { |
| 904 | xenbus_dev_fatal(dev, err, |
| 905 | "reading %s/event-channel(-tx/rx)", |
| 906 | xspath); |
| 907 | goto err; |
| 908 | } |
| 909 | rx_evtchn = tx_evtchn; |
| 910 | } |
| 911 | |
| 912 | /* Map the shared frame, irq etc. */ |
| 913 | err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref, |
| 914 | tx_evtchn, rx_evtchn); |
| 915 | if (err) { |
| 916 | xenbus_dev_fatal(dev, err, |
| 917 | "mapping shared-frames %lu/%lu port tx %u rx %u", |
| 918 | tx_ring_ref, rx_ring_ref, |
| 919 | tx_evtchn, rx_evtchn); |
| 920 | goto err; |
| 921 | } |
| 922 | |
| 923 | err = 0; |
| 924 | err: /* Regular return falls through with err == 0 */ |
| 925 | kfree(xspath); |
| 926 | return err; |
| 927 | } |
| 928 | |
| 929 | static int read_xenbus_vif_flags(struct backend_info *be) |
| 930 | { |
| 931 | struct xenvif *vif = be->vif; |
| 932 | struct xenbus_device *dev = be->dev; |
| 933 | unsigned int rx_copy; |
| 934 | int err; |
| 935 | |
| 936 | err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u", |
| 937 | &rx_copy); |
| 938 | if (err == -ENOENT) { |
| 939 | err = 0; |
| 940 | rx_copy = 0; |
| 941 | } |
| 942 | if (err < 0) { |
| 943 | xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy", |
| 944 | dev->otherend); |
| 945 | return err; |
| 946 | } |
| 947 | if (!rx_copy) |
| 948 | return -EOPNOTSUPP; |
| 949 | |
| 950 | if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) { |
| 951 | /* - Reduce drain timeout to poll more frequently for |
| 952 | * Rx requests. |
| 953 | * - Disable Rx stall detection. |
| 954 | */ |
| 955 | be->vif->drain_timeout = msecs_to_jiffies(30); |
| 956 | be->vif->stall_timeout = 0; |
| 957 | } |
| 958 | |
| 959 | vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0); |
| 960 | |
| 961 | vif->gso_mask = 0; |
| 962 | |
| 963 | if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0)) |
| 964 | vif->gso_mask |= GSO_BIT(TCPV4); |
| 965 | |
| 966 | if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0)) |
| 967 | vif->gso_mask |= GSO_BIT(TCPV6); |
| 968 | |
| 969 | vif->ip_csum = !xenbus_read_unsigned(dev->otherend, |
| 970 | "feature-no-csum-offload", 0); |
| 971 | |
| 972 | vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend, |
| 973 | "feature-ipv6-csum-offload", 0); |
| 974 | |
| 975 | read_xenbus_frontend_xdp(be, dev); |
| 976 | |
| 977 | return 0; |
| 978 | } |
| 979 | |
| 980 | static void netback_remove(struct xenbus_device *dev) |
| 981 | { |
| 982 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
| 983 | |
| 984 | unregister_hotplug_status_watch(be); |
| 985 | xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status"); |
| 986 | if (be->vif) { |
| 987 | kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE); |
| 988 | backend_disconnect(be); |
| 989 | xenvif_free(be->vif); |
| 990 | be->vif = NULL; |
| 991 | } |
| 992 | kfree(be->hotplug_script); |
| 993 | kfree(be); |
| 994 | dev_set_drvdata(&dev->dev, NULL); |
| 995 | } |
| 996 | |
| 997 | /* |
| 998 | * Entry point to this code when a new device is created. Allocate the basic |
| 999 | * structures and switch to InitWait. |
| 1000 | */ |
| 1001 | static int netback_probe(struct xenbus_device *dev, |
| 1002 | const struct xenbus_device_id *id) |
| 1003 | { |
| 1004 | const char *message; |
| 1005 | struct xenbus_transaction xbt; |
| 1006 | int err; |
| 1007 | int sg; |
| 1008 | const char *script; |
| 1009 | struct backend_info *be = kzalloc(sizeof(*be), GFP_KERNEL); |
| 1010 | |
| 1011 | if (!be) { |
| 1012 | xenbus_dev_fatal(dev, -ENOMEM, |
| 1013 | "allocating backend structure"); |
| 1014 | return -ENOMEM; |
| 1015 | } |
| 1016 | |
| 1017 | be->dev = dev; |
| 1018 | dev_set_drvdata(&dev->dev, be); |
| 1019 | |
| 1020 | sg = 1; |
| 1021 | |
| 1022 | do { |
| 1023 | err = xenbus_transaction_start(&xbt); |
| 1024 | if (err) { |
| 1025 | xenbus_dev_fatal(dev, err, "starting transaction"); |
| 1026 | goto fail; |
| 1027 | } |
| 1028 | |
| 1029 | err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg); |
| 1030 | if (err) { |
| 1031 | message = "writing feature-sg"; |
| 1032 | goto abort_transaction; |
| 1033 | } |
| 1034 | |
| 1035 | err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", |
| 1036 | "%d", sg); |
| 1037 | if (err) { |
| 1038 | message = "writing feature-gso-tcpv4"; |
| 1039 | goto abort_transaction; |
| 1040 | } |
| 1041 | |
| 1042 | err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6", |
| 1043 | "%d", sg); |
| 1044 | if (err) { |
| 1045 | message = "writing feature-gso-tcpv6"; |
| 1046 | goto abort_transaction; |
| 1047 | } |
| 1048 | |
| 1049 | /* We support partial checksum setup for IPv6 packets */ |
| 1050 | err = xenbus_printf(xbt, dev->nodename, |
| 1051 | "feature-ipv6-csum-offload", |
| 1052 | "%d", 1); |
| 1053 | if (err) { |
| 1054 | message = "writing feature-ipv6-csum-offload"; |
| 1055 | goto abort_transaction; |
| 1056 | } |
| 1057 | |
| 1058 | /* We support rx-copy path. */ |
| 1059 | err = xenbus_printf(xbt, dev->nodename, |
| 1060 | "feature-rx-copy", "%d", 1); |
| 1061 | if (err) { |
| 1062 | message = "writing feature-rx-copy"; |
| 1063 | goto abort_transaction; |
| 1064 | } |
| 1065 | |
| 1066 | /* we can adjust a headroom for netfront XDP processing */ |
| 1067 | err = xenbus_printf(xbt, dev->nodename, |
| 1068 | "feature-xdp-headroom", "%d", |
| 1069 | provides_xdp_headroom); |
| 1070 | if (err) { |
| 1071 | message = "writing feature-xdp-headroom"; |
| 1072 | goto abort_transaction; |
| 1073 | } |
| 1074 | |
| 1075 | /* We don't support rx-flip path (except old guests who |
| 1076 | * don't grok this feature flag). |
| 1077 | */ |
| 1078 | err = xenbus_printf(xbt, dev->nodename, |
| 1079 | "feature-rx-flip", "%d", 0); |
| 1080 | if (err) { |
| 1081 | message = "writing feature-rx-flip"; |
| 1082 | goto abort_transaction; |
| 1083 | } |
| 1084 | |
| 1085 | /* We support dynamic multicast-control. */ |
| 1086 | err = xenbus_printf(xbt, dev->nodename, |
| 1087 | "feature-multicast-control", "%d", 1); |
| 1088 | if (err) { |
| 1089 | message = "writing feature-multicast-control"; |
| 1090 | goto abort_transaction; |
| 1091 | } |
| 1092 | |
| 1093 | err = xenbus_printf(xbt, dev->nodename, |
| 1094 | "feature-dynamic-multicast-control", |
| 1095 | "%d", 1); |
| 1096 | if (err) { |
| 1097 | message = "writing feature-dynamic-multicast-control"; |
| 1098 | goto abort_transaction; |
| 1099 | } |
| 1100 | |
| 1101 | err = xenbus_transaction_end(xbt, 0); |
| 1102 | } while (err == -EAGAIN); |
| 1103 | |
| 1104 | if (err) { |
| 1105 | xenbus_dev_fatal(dev, err, "completing transaction"); |
| 1106 | goto fail; |
| 1107 | } |
| 1108 | |
| 1109 | /* Split event channels support, this is optional so it is not |
| 1110 | * put inside the above loop. |
| 1111 | */ |
| 1112 | err = xenbus_printf(XBT_NIL, dev->nodename, |
| 1113 | "feature-split-event-channels", |
| 1114 | "%u", separate_tx_rx_irq); |
| 1115 | if (err) |
| 1116 | pr_debug("Error writing feature-split-event-channels\n"); |
| 1117 | |
| 1118 | /* Multi-queue support: This is an optional feature. */ |
| 1119 | err = xenbus_printf(XBT_NIL, dev->nodename, |
| 1120 | "multi-queue-max-queues", "%u", xenvif_max_queues); |
| 1121 | if (err) |
| 1122 | pr_debug("Error writing multi-queue-max-queues\n"); |
| 1123 | |
| 1124 | err = xenbus_printf(XBT_NIL, dev->nodename, |
| 1125 | "feature-ctrl-ring", |
| 1126 | "%u", true); |
| 1127 | if (err) |
| 1128 | pr_debug("Error writing feature-ctrl-ring\n"); |
| 1129 | |
| 1130 | backend_switch_state(be, XenbusStateInitWait); |
| 1131 | |
| 1132 | script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL); |
| 1133 | if (IS_ERR(script)) { |
| 1134 | err = PTR_ERR(script); |
| 1135 | xenbus_dev_fatal(dev, err, "reading script"); |
| 1136 | goto fail; |
| 1137 | } |
| 1138 | |
| 1139 | be->hotplug_script = script; |
| 1140 | |
| 1141 | /* This kicks hotplug scripts, so do it immediately. */ |
| 1142 | err = backend_create_xenvif(be); |
| 1143 | if (err) |
| 1144 | goto fail; |
| 1145 | |
| 1146 | return 0; |
| 1147 | |
| 1148 | abort_transaction: |
| 1149 | xenbus_transaction_end(xbt, 1); |
| 1150 | xenbus_dev_fatal(dev, err, "%s", message); |
| 1151 | fail: |
| 1152 | pr_debug("failed\n"); |
| 1153 | netback_remove(dev); |
| 1154 | return err; |
| 1155 | } |
| 1156 | |
| 1157 | static const struct xenbus_device_id netback_ids[] = { |
| 1158 | { "vif" }, |
| 1159 | { "" } |
| 1160 | }; |
| 1161 | |
| 1162 | static struct xenbus_driver netback_driver = { |
| 1163 | .ids = netback_ids, |
| 1164 | .probe = netback_probe, |
| 1165 | .remove = netback_remove, |
| 1166 | .uevent = netback_uevent, |
| 1167 | .otherend_changed = frontend_changed, |
| 1168 | .allow_rebind = true, |
| 1169 | }; |
| 1170 | |
| 1171 | int xenvif_xenbus_init(void) |
| 1172 | { |
| 1173 | return xenbus_register_backend(&netback_driver); |
| 1174 | } |
| 1175 | |
| 1176 | void xenvif_xenbus_fini(void) |
| 1177 | { |
| 1178 | return xenbus_unregister_driver(&netback_driver); |
| 1179 | } |