1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2009, Microsoft Corporation. 4 * 5 * Authors: 6 * Haiyang Zhang <haiyangz@microsoft.com> 7 * Hank Janssen <hjanssen@microsoft.com> 8 * K. Y. Srinivasan <kys@microsoft.com> 9 */ 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/device.h> 15 #include <linux/interrupt.h> 16 #include <linux/sysctl.h> 17 #include <linux/slab.h> 18 #include <linux/acpi.h> 19 #include <linux/completion.h> 20 #include <linux/hyperv.h> 21 #include <linux/kernel_stat.h> 22 #include <linux/clockchips.h> 23 #include <linux/cpu.h> 24 #include <linux/sched/task_stack.h> 25 26 #include <linux/delay.h> 27 #include <linux/notifier.h> 28 #include <linux/panic_notifier.h> 29 #include <linux/ptrace.h> 30 #include <linux/screen_info.h> 31 #include <linux/kdebug.h> 32 #include <linux/efi.h> 33 #include <linux/random.h> 34 #include <linux/kernel.h> 35 #include <linux/syscore_ops.h> 36 #include <linux/dma-map-ops.h> 37 #include <clocksource/hyperv_timer.h> 38 #include "hyperv_vmbus.h" 39 40 struct vmbus_dynid { 41 struct list_head node; 42 struct hv_vmbus_device_id id; 43 }; 44 45 static struct acpi_device *hv_acpi_dev; 46 47 static struct completion probe_event; 48 49 static int hyperv_cpuhp_online; 50 51 static void *hv_panic_page; 52 53 static long __percpu *vmbus_evt; 54 55 /* Values parsed from ACPI DSDT */ 56 int vmbus_irq; 57 int vmbus_interrupt; 58 59 /* 60 * Boolean to control whether to report panic messages over Hyper-V. 61 * 62 * It can be set via /proc/sys/kernel/hyperv_record_panic_msg 63 */ 64 static int sysctl_record_panic_msg = 1; 65 66 static int hyperv_report_reg(void) 67 { 68 return !sysctl_record_panic_msg || !hv_panic_page; 69 } 70 71 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val, 72 void *args) 73 { 74 struct pt_regs *regs; 75 76 vmbus_initiate_unload(true); 77 78 /* 79 * Hyper-V should be notified only once about a panic. If we will be 80 * doing hyperv_report_panic_msg() later with kmsg data, don't do 81 * the notification here. 82 */ 83 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE 84 && hyperv_report_reg()) { 85 regs = current_pt_regs(); 86 hyperv_report_panic(regs, val, false); 87 } 88 return NOTIFY_DONE; 89 } 90 91 static int hyperv_die_event(struct notifier_block *nb, unsigned long val, 92 void *args) 93 { 94 struct die_args *die = args; 95 struct pt_regs *regs = die->regs; 96 97 /* Don't notify Hyper-V if the die event is other than oops */ 98 if (val != DIE_OOPS) 99 return NOTIFY_DONE; 100 101 /* 102 * Hyper-V should be notified only once about a panic. If we will be 103 * doing hyperv_report_panic_msg() later with kmsg data, don't do 104 * the notification here. 105 */ 106 if (hyperv_report_reg()) 107 hyperv_report_panic(regs, val, true); 108 return NOTIFY_DONE; 109 } 110 111 static struct notifier_block hyperv_die_block = { 112 .notifier_call = hyperv_die_event, 113 }; 114 static struct notifier_block hyperv_panic_block = { 115 .notifier_call = hyperv_panic_event, 116 }; 117 118 static const char *fb_mmio_name = "fb_range"; 119 static struct resource *fb_mmio; 120 static struct resource *hyperv_mmio; 121 static DEFINE_MUTEX(hyperv_mmio_lock); 122 123 static int vmbus_exists(void) 124 { 125 if (hv_acpi_dev == NULL) 126 return -ENODEV; 127 128 return 0; 129 } 130 131 static u8 channel_monitor_group(const struct vmbus_channel *channel) 132 { 133 return (u8)channel->offermsg.monitorid / 32; 134 } 135 136 static u8 channel_monitor_offset(const struct vmbus_channel *channel) 137 { 138 return (u8)channel->offermsg.monitorid % 32; 139 } 140 141 static u32 channel_pending(const struct vmbus_channel *channel, 142 const struct hv_monitor_page *monitor_page) 143 { 144 u8 monitor_group = channel_monitor_group(channel); 145 146 return monitor_page->trigger_group[monitor_group].pending; 147 } 148 149 static u32 channel_latency(const struct vmbus_channel *channel, 150 const struct hv_monitor_page *monitor_page) 151 { 152 u8 monitor_group = channel_monitor_group(channel); 153 u8 monitor_offset = channel_monitor_offset(channel); 154 155 return monitor_page->latency[monitor_group][monitor_offset]; 156 } 157 158 static u32 channel_conn_id(struct vmbus_channel *channel, 159 struct hv_monitor_page *monitor_page) 160 { 161 u8 monitor_group = channel_monitor_group(channel); 162 u8 monitor_offset = channel_monitor_offset(channel); 163 164 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id; 165 } 166 167 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr, 168 char *buf) 169 { 170 struct hv_device *hv_dev = device_to_hv_device(dev); 171 172 if (!hv_dev->channel) 173 return -ENODEV; 174 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid); 175 } 176 static DEVICE_ATTR_RO(id); 177 178 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr, 179 char *buf) 180 { 181 struct hv_device *hv_dev = device_to_hv_device(dev); 182 183 if (!hv_dev->channel) 184 return -ENODEV; 185 return sprintf(buf, "%d\n", hv_dev->channel->state); 186 } 187 static DEVICE_ATTR_RO(state); 188 189 static ssize_t monitor_id_show(struct device *dev, 190 struct device_attribute *dev_attr, char *buf) 191 { 192 struct hv_device *hv_dev = device_to_hv_device(dev); 193 194 if (!hv_dev->channel) 195 return -ENODEV; 196 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid); 197 } 198 static DEVICE_ATTR_RO(monitor_id); 199 200 static ssize_t class_id_show(struct device *dev, 201 struct device_attribute *dev_attr, char *buf) 202 { 203 struct hv_device *hv_dev = device_to_hv_device(dev); 204 205 if (!hv_dev->channel) 206 return -ENODEV; 207 return sprintf(buf, "{%pUl}\n", 208 &hv_dev->channel->offermsg.offer.if_type); 209 } 210 static DEVICE_ATTR_RO(class_id); 211 212 static ssize_t device_id_show(struct device *dev, 213 struct device_attribute *dev_attr, char *buf) 214 { 215 struct hv_device *hv_dev = device_to_hv_device(dev); 216 217 if (!hv_dev->channel) 218 return -ENODEV; 219 return sprintf(buf, "{%pUl}\n", 220 &hv_dev->channel->offermsg.offer.if_instance); 221 } 222 static DEVICE_ATTR_RO(device_id); 223 224 static ssize_t modalias_show(struct device *dev, 225 struct device_attribute *dev_attr, char *buf) 226 { 227 struct hv_device *hv_dev = device_to_hv_device(dev); 228 229 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type); 230 } 231 static DEVICE_ATTR_RO(modalias); 232 233 #ifdef CONFIG_NUMA 234 static ssize_t numa_node_show(struct device *dev, 235 struct device_attribute *attr, char *buf) 236 { 237 struct hv_device *hv_dev = device_to_hv_device(dev); 238 239 if (!hv_dev->channel) 240 return -ENODEV; 241 242 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu)); 243 } 244 static DEVICE_ATTR_RO(numa_node); 245 #endif 246 247 static ssize_t server_monitor_pending_show(struct device *dev, 248 struct device_attribute *dev_attr, 249 char *buf) 250 { 251 struct hv_device *hv_dev = device_to_hv_device(dev); 252 253 if (!hv_dev->channel) 254 return -ENODEV; 255 return sprintf(buf, "%d\n", 256 channel_pending(hv_dev->channel, 257 vmbus_connection.monitor_pages[0])); 258 } 259 static DEVICE_ATTR_RO(server_monitor_pending); 260 261 static ssize_t client_monitor_pending_show(struct device *dev, 262 struct device_attribute *dev_attr, 263 char *buf) 264 { 265 struct hv_device *hv_dev = device_to_hv_device(dev); 266 267 if (!hv_dev->channel) 268 return -ENODEV; 269 return sprintf(buf, "%d\n", 270 channel_pending(hv_dev->channel, 271 vmbus_connection.monitor_pages[1])); 272 } 273 static DEVICE_ATTR_RO(client_monitor_pending); 274 275 static ssize_t server_monitor_latency_show(struct device *dev, 276 struct device_attribute *dev_attr, 277 char *buf) 278 { 279 struct hv_device *hv_dev = device_to_hv_device(dev); 280 281 if (!hv_dev->channel) 282 return -ENODEV; 283 return sprintf(buf, "%d\n", 284 channel_latency(hv_dev->channel, 285 vmbus_connection.monitor_pages[0])); 286 } 287 static DEVICE_ATTR_RO(server_monitor_latency); 288 289 static ssize_t client_monitor_latency_show(struct device *dev, 290 struct device_attribute *dev_attr, 291 char *buf) 292 { 293 struct hv_device *hv_dev = device_to_hv_device(dev); 294 295 if (!hv_dev->channel) 296 return -ENODEV; 297 return sprintf(buf, "%d\n", 298 channel_latency(hv_dev->channel, 299 vmbus_connection.monitor_pages[1])); 300 } 301 static DEVICE_ATTR_RO(client_monitor_latency); 302 303 static ssize_t server_monitor_conn_id_show(struct device *dev, 304 struct device_attribute *dev_attr, 305 char *buf) 306 { 307 struct hv_device *hv_dev = device_to_hv_device(dev); 308 309 if (!hv_dev->channel) 310 return -ENODEV; 311 return sprintf(buf, "%d\n", 312 channel_conn_id(hv_dev->channel, 313 vmbus_connection.monitor_pages[0])); 314 } 315 static DEVICE_ATTR_RO(server_monitor_conn_id); 316 317 static ssize_t client_monitor_conn_id_show(struct device *dev, 318 struct device_attribute *dev_attr, 319 char *buf) 320 { 321 struct hv_device *hv_dev = device_to_hv_device(dev); 322 323 if (!hv_dev->channel) 324 return -ENODEV; 325 return sprintf(buf, "%d\n", 326 channel_conn_id(hv_dev->channel, 327 vmbus_connection.monitor_pages[1])); 328 } 329 static DEVICE_ATTR_RO(client_monitor_conn_id); 330 331 static ssize_t out_intr_mask_show(struct device *dev, 332 struct device_attribute *dev_attr, char *buf) 333 { 334 struct hv_device *hv_dev = device_to_hv_device(dev); 335 struct hv_ring_buffer_debug_info outbound; 336 int ret; 337 338 if (!hv_dev->channel) 339 return -ENODEV; 340 341 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 342 &outbound); 343 if (ret < 0) 344 return ret; 345 346 return sprintf(buf, "%d\n", outbound.current_interrupt_mask); 347 } 348 static DEVICE_ATTR_RO(out_intr_mask); 349 350 static ssize_t out_read_index_show(struct device *dev, 351 struct device_attribute *dev_attr, char *buf) 352 { 353 struct hv_device *hv_dev = device_to_hv_device(dev); 354 struct hv_ring_buffer_debug_info outbound; 355 int ret; 356 357 if (!hv_dev->channel) 358 return -ENODEV; 359 360 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 361 &outbound); 362 if (ret < 0) 363 return ret; 364 return sprintf(buf, "%d\n", outbound.current_read_index); 365 } 366 static DEVICE_ATTR_RO(out_read_index); 367 368 static ssize_t out_write_index_show(struct device *dev, 369 struct device_attribute *dev_attr, 370 char *buf) 371 { 372 struct hv_device *hv_dev = device_to_hv_device(dev); 373 struct hv_ring_buffer_debug_info outbound; 374 int ret; 375 376 if (!hv_dev->channel) 377 return -ENODEV; 378 379 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 380 &outbound); 381 if (ret < 0) 382 return ret; 383 return sprintf(buf, "%d\n", outbound.current_write_index); 384 } 385 static DEVICE_ATTR_RO(out_write_index); 386 387 static ssize_t out_read_bytes_avail_show(struct device *dev, 388 struct device_attribute *dev_attr, 389 char *buf) 390 { 391 struct hv_device *hv_dev = device_to_hv_device(dev); 392 struct hv_ring_buffer_debug_info outbound; 393 int ret; 394 395 if (!hv_dev->channel) 396 return -ENODEV; 397 398 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 399 &outbound); 400 if (ret < 0) 401 return ret; 402 return sprintf(buf, "%d\n", outbound.bytes_avail_toread); 403 } 404 static DEVICE_ATTR_RO(out_read_bytes_avail); 405 406 static ssize_t out_write_bytes_avail_show(struct device *dev, 407 struct device_attribute *dev_attr, 408 char *buf) 409 { 410 struct hv_device *hv_dev = device_to_hv_device(dev); 411 struct hv_ring_buffer_debug_info outbound; 412 int ret; 413 414 if (!hv_dev->channel) 415 return -ENODEV; 416 417 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 418 &outbound); 419 if (ret < 0) 420 return ret; 421 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite); 422 } 423 static DEVICE_ATTR_RO(out_write_bytes_avail); 424 425 static ssize_t in_intr_mask_show(struct device *dev, 426 struct device_attribute *dev_attr, char *buf) 427 { 428 struct hv_device *hv_dev = device_to_hv_device(dev); 429 struct hv_ring_buffer_debug_info inbound; 430 int ret; 431 432 if (!hv_dev->channel) 433 return -ENODEV; 434 435 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 436 if (ret < 0) 437 return ret; 438 439 return sprintf(buf, "%d\n", inbound.current_interrupt_mask); 440 } 441 static DEVICE_ATTR_RO(in_intr_mask); 442 443 static ssize_t in_read_index_show(struct device *dev, 444 struct device_attribute *dev_attr, char *buf) 445 { 446 struct hv_device *hv_dev = device_to_hv_device(dev); 447 struct hv_ring_buffer_debug_info inbound; 448 int ret; 449 450 if (!hv_dev->channel) 451 return -ENODEV; 452 453 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 454 if (ret < 0) 455 return ret; 456 457 return sprintf(buf, "%d\n", inbound.current_read_index); 458 } 459 static DEVICE_ATTR_RO(in_read_index); 460 461 static ssize_t in_write_index_show(struct device *dev, 462 struct device_attribute *dev_attr, char *buf) 463 { 464 struct hv_device *hv_dev = device_to_hv_device(dev); 465 struct hv_ring_buffer_debug_info inbound; 466 int ret; 467 468 if (!hv_dev->channel) 469 return -ENODEV; 470 471 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 472 if (ret < 0) 473 return ret; 474 475 return sprintf(buf, "%d\n", inbound.current_write_index); 476 } 477 static DEVICE_ATTR_RO(in_write_index); 478 479 static ssize_t in_read_bytes_avail_show(struct device *dev, 480 struct device_attribute *dev_attr, 481 char *buf) 482 { 483 struct hv_device *hv_dev = device_to_hv_device(dev); 484 struct hv_ring_buffer_debug_info inbound; 485 int ret; 486 487 if (!hv_dev->channel) 488 return -ENODEV; 489 490 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 491 if (ret < 0) 492 return ret; 493 494 return sprintf(buf, "%d\n", inbound.bytes_avail_toread); 495 } 496 static DEVICE_ATTR_RO(in_read_bytes_avail); 497 498 static ssize_t in_write_bytes_avail_show(struct device *dev, 499 struct device_attribute *dev_attr, 500 char *buf) 501 { 502 struct hv_device *hv_dev = device_to_hv_device(dev); 503 struct hv_ring_buffer_debug_info inbound; 504 int ret; 505 506 if (!hv_dev->channel) 507 return -ENODEV; 508 509 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 510 if (ret < 0) 511 return ret; 512 513 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite); 514 } 515 static DEVICE_ATTR_RO(in_write_bytes_avail); 516 517 static ssize_t channel_vp_mapping_show(struct device *dev, 518 struct device_attribute *dev_attr, 519 char *buf) 520 { 521 struct hv_device *hv_dev = device_to_hv_device(dev); 522 struct vmbus_channel *channel = hv_dev->channel, *cur_sc; 523 int buf_size = PAGE_SIZE, n_written, tot_written; 524 struct list_head *cur; 525 526 if (!channel) 527 return -ENODEV; 528 529 mutex_lock(&vmbus_connection.channel_mutex); 530 531 tot_written = snprintf(buf, buf_size, "%u:%u\n", 532 channel->offermsg.child_relid, channel->target_cpu); 533 534 list_for_each(cur, &channel->sc_list) { 535 if (tot_written >= buf_size - 1) 536 break; 537 538 cur_sc = list_entry(cur, struct vmbus_channel, sc_list); 539 n_written = scnprintf(buf + tot_written, 540 buf_size - tot_written, 541 "%u:%u\n", 542 cur_sc->offermsg.child_relid, 543 cur_sc->target_cpu); 544 tot_written += n_written; 545 } 546 547 mutex_unlock(&vmbus_connection.channel_mutex); 548 549 return tot_written; 550 } 551 static DEVICE_ATTR_RO(channel_vp_mapping); 552 553 static ssize_t vendor_show(struct device *dev, 554 struct device_attribute *dev_attr, 555 char *buf) 556 { 557 struct hv_device *hv_dev = device_to_hv_device(dev); 558 559 return sprintf(buf, "0x%x\n", hv_dev->vendor_id); 560 } 561 static DEVICE_ATTR_RO(vendor); 562 563 static ssize_t device_show(struct device *dev, 564 struct device_attribute *dev_attr, 565 char *buf) 566 { 567 struct hv_device *hv_dev = device_to_hv_device(dev); 568 569 return sprintf(buf, "0x%x\n", hv_dev->device_id); 570 } 571 static DEVICE_ATTR_RO(device); 572 573 static ssize_t driver_override_store(struct device *dev, 574 struct device_attribute *attr, 575 const char *buf, size_t count) 576 { 577 struct hv_device *hv_dev = device_to_hv_device(dev); 578 char *driver_override, *old, *cp; 579 580 /* We need to keep extra room for a newline */ 581 if (count >= (PAGE_SIZE - 1)) 582 return -EINVAL; 583 584 driver_override = kstrndup(buf, count, GFP_KERNEL); 585 if (!driver_override) 586 return -ENOMEM; 587 588 cp = strchr(driver_override, '\n'); 589 if (cp) 590 *cp = '\0'; 591 592 device_lock(dev); 593 old = hv_dev->driver_override; 594 if (strlen(driver_override)) { 595 hv_dev->driver_override = driver_override; 596 } else { 597 kfree(driver_override); 598 hv_dev->driver_override = NULL; 599 } 600 device_unlock(dev); 601 602 kfree(old); 603 604 return count; 605 } 606 607 static ssize_t driver_override_show(struct device *dev, 608 struct device_attribute *attr, char *buf) 609 { 610 struct hv_device *hv_dev = device_to_hv_device(dev); 611 ssize_t len; 612 613 device_lock(dev); 614 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override); 615 device_unlock(dev); 616 617 return len; 618 } 619 static DEVICE_ATTR_RW(driver_override); 620 621 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */ 622 static struct attribute *vmbus_dev_attrs[] = { 623 &dev_attr_id.attr, 624 &dev_attr_state.attr, 625 &dev_attr_monitor_id.attr, 626 &dev_attr_class_id.attr, 627 &dev_attr_device_id.attr, 628 &dev_attr_modalias.attr, 629 #ifdef CONFIG_NUMA 630 &dev_attr_numa_node.attr, 631 #endif 632 &dev_attr_server_monitor_pending.attr, 633 &dev_attr_client_monitor_pending.attr, 634 &dev_attr_server_monitor_latency.attr, 635 &dev_attr_client_monitor_latency.attr, 636 &dev_attr_server_monitor_conn_id.attr, 637 &dev_attr_client_monitor_conn_id.attr, 638 &dev_attr_out_intr_mask.attr, 639 &dev_attr_out_read_index.attr, 640 &dev_attr_out_write_index.attr, 641 &dev_attr_out_read_bytes_avail.attr, 642 &dev_attr_out_write_bytes_avail.attr, 643 &dev_attr_in_intr_mask.attr, 644 &dev_attr_in_read_index.attr, 645 &dev_attr_in_write_index.attr, 646 &dev_attr_in_read_bytes_avail.attr, 647 &dev_attr_in_write_bytes_avail.attr, 648 &dev_attr_channel_vp_mapping.attr, 649 &dev_attr_vendor.attr, 650 &dev_attr_device.attr, 651 &dev_attr_driver_override.attr, 652 NULL, 653 }; 654 655 /* 656 * Device-level attribute_group callback function. Returns the permission for 657 * each attribute, and returns 0 if an attribute is not visible. 658 */ 659 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj, 660 struct attribute *attr, int idx) 661 { 662 struct device *dev = kobj_to_dev(kobj); 663 const struct hv_device *hv_dev = device_to_hv_device(dev); 664 665 /* Hide the monitor attributes if the monitor mechanism is not used. */ 666 if (!hv_dev->channel->offermsg.monitor_allocated && 667 (attr == &dev_attr_monitor_id.attr || 668 attr == &dev_attr_server_monitor_pending.attr || 669 attr == &dev_attr_client_monitor_pending.attr || 670 attr == &dev_attr_server_monitor_latency.attr || 671 attr == &dev_attr_client_monitor_latency.attr || 672 attr == &dev_attr_server_monitor_conn_id.attr || 673 attr == &dev_attr_client_monitor_conn_id.attr)) 674 return 0; 675 676 return attr->mode; 677 } 678 679 static const struct attribute_group vmbus_dev_group = { 680 .attrs = vmbus_dev_attrs, 681 .is_visible = vmbus_dev_attr_is_visible 682 }; 683 __ATTRIBUTE_GROUPS(vmbus_dev); 684 685 /* Set up the attribute for /sys/bus/vmbus/hibernation */ 686 static ssize_t hibernation_show(struct bus_type *bus, char *buf) 687 { 688 return sprintf(buf, "%d\n", !!hv_is_hibernation_supported()); 689 } 690 691 static BUS_ATTR_RO(hibernation); 692 693 static struct attribute *vmbus_bus_attrs[] = { 694 &bus_attr_hibernation.attr, 695 NULL, 696 }; 697 static const struct attribute_group vmbus_bus_group = { 698 .attrs = vmbus_bus_attrs, 699 }; 700 __ATTRIBUTE_GROUPS(vmbus_bus); 701 702 /* 703 * vmbus_uevent - add uevent for our device 704 * 705 * This routine is invoked when a device is added or removed on the vmbus to 706 * generate a uevent to udev in the userspace. The udev will then look at its 707 * rule and the uevent generated here to load the appropriate driver 708 * 709 * The alias string will be of the form vmbus:guid where guid is the string 710 * representation of the device guid (each byte of the guid will be 711 * represented with two hex characters. 712 */ 713 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env) 714 { 715 struct hv_device *dev = device_to_hv_device(device); 716 const char *format = "MODALIAS=vmbus:%*phN"; 717 718 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type); 719 } 720 721 static const struct hv_vmbus_device_id * 722 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid) 723 { 724 if (id == NULL) 725 return NULL; /* empty device table */ 726 727 for (; !guid_is_null(&id->guid); id++) 728 if (guid_equal(&id->guid, guid)) 729 return id; 730 731 return NULL; 732 } 733 734 static const struct hv_vmbus_device_id * 735 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid) 736 { 737 const struct hv_vmbus_device_id *id = NULL; 738 struct vmbus_dynid *dynid; 739 740 spin_lock(&drv->dynids.lock); 741 list_for_each_entry(dynid, &drv->dynids.list, node) { 742 if (guid_equal(&dynid->id.guid, guid)) { 743 id = &dynid->id; 744 break; 745 } 746 } 747 spin_unlock(&drv->dynids.lock); 748 749 return id; 750 } 751 752 static const struct hv_vmbus_device_id vmbus_device_null; 753 754 /* 755 * Return a matching hv_vmbus_device_id pointer. 756 * If there is no match, return NULL. 757 */ 758 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv, 759 struct hv_device *dev) 760 { 761 const guid_t *guid = &dev->dev_type; 762 const struct hv_vmbus_device_id *id; 763 764 /* When driver_override is set, only bind to the matching driver */ 765 if (dev->driver_override && strcmp(dev->driver_override, drv->name)) 766 return NULL; 767 768 /* Look at the dynamic ids first, before the static ones */ 769 id = hv_vmbus_dynid_match(drv, guid); 770 if (!id) 771 id = hv_vmbus_dev_match(drv->id_table, guid); 772 773 /* driver_override will always match, send a dummy id */ 774 if (!id && dev->driver_override) 775 id = &vmbus_device_null; 776 777 return id; 778 } 779 780 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */ 781 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid) 782 { 783 struct vmbus_dynid *dynid; 784 785 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL); 786 if (!dynid) 787 return -ENOMEM; 788 789 dynid->id.guid = *guid; 790 791 spin_lock(&drv->dynids.lock); 792 list_add_tail(&dynid->node, &drv->dynids.list); 793 spin_unlock(&drv->dynids.lock); 794 795 return driver_attach(&drv->driver); 796 } 797 798 static void vmbus_free_dynids(struct hv_driver *drv) 799 { 800 struct vmbus_dynid *dynid, *n; 801 802 spin_lock(&drv->dynids.lock); 803 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 804 list_del(&dynid->node); 805 kfree(dynid); 806 } 807 spin_unlock(&drv->dynids.lock); 808 } 809 810 /* 811 * store_new_id - sysfs frontend to vmbus_add_dynid() 812 * 813 * Allow GUIDs to be added to an existing driver via sysfs. 814 */ 815 static ssize_t new_id_store(struct device_driver *driver, const char *buf, 816 size_t count) 817 { 818 struct hv_driver *drv = drv_to_hv_drv(driver); 819 guid_t guid; 820 ssize_t retval; 821 822 retval = guid_parse(buf, &guid); 823 if (retval) 824 return retval; 825 826 if (hv_vmbus_dynid_match(drv, &guid)) 827 return -EEXIST; 828 829 retval = vmbus_add_dynid(drv, &guid); 830 if (retval) 831 return retval; 832 return count; 833 } 834 static DRIVER_ATTR_WO(new_id); 835 836 /* 837 * store_remove_id - remove a PCI device ID from this driver 838 * 839 * Removes a dynamic pci device ID to this driver. 840 */ 841 static ssize_t remove_id_store(struct device_driver *driver, const char *buf, 842 size_t count) 843 { 844 struct hv_driver *drv = drv_to_hv_drv(driver); 845 struct vmbus_dynid *dynid, *n; 846 guid_t guid; 847 ssize_t retval; 848 849 retval = guid_parse(buf, &guid); 850 if (retval) 851 return retval; 852 853 retval = -ENODEV; 854 spin_lock(&drv->dynids.lock); 855 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 856 struct hv_vmbus_device_id *id = &dynid->id; 857 858 if (guid_equal(&id->guid, &guid)) { 859 list_del(&dynid->node); 860 kfree(dynid); 861 retval = count; 862 break; 863 } 864 } 865 spin_unlock(&drv->dynids.lock); 866 867 return retval; 868 } 869 static DRIVER_ATTR_WO(remove_id); 870 871 static struct attribute *vmbus_drv_attrs[] = { 872 &driver_attr_new_id.attr, 873 &driver_attr_remove_id.attr, 874 NULL, 875 }; 876 ATTRIBUTE_GROUPS(vmbus_drv); 877 878 879 /* 880 * vmbus_match - Attempt to match the specified device to the specified driver 881 */ 882 static int vmbus_match(struct device *device, struct device_driver *driver) 883 { 884 struct hv_driver *drv = drv_to_hv_drv(driver); 885 struct hv_device *hv_dev = device_to_hv_device(device); 886 887 /* The hv_sock driver handles all hv_sock offers. */ 888 if (is_hvsock_channel(hv_dev->channel)) 889 return drv->hvsock; 890 891 if (hv_vmbus_get_id(drv, hv_dev)) 892 return 1; 893 894 return 0; 895 } 896 897 /* 898 * vmbus_probe - Add the new vmbus's child device 899 */ 900 static int vmbus_probe(struct device *child_device) 901 { 902 int ret = 0; 903 struct hv_driver *drv = 904 drv_to_hv_drv(child_device->driver); 905 struct hv_device *dev = device_to_hv_device(child_device); 906 const struct hv_vmbus_device_id *dev_id; 907 908 dev_id = hv_vmbus_get_id(drv, dev); 909 if (drv->probe) { 910 ret = drv->probe(dev, dev_id); 911 if (ret != 0) 912 pr_err("probe failed for device %s (%d)\n", 913 dev_name(child_device), ret); 914 915 } else { 916 pr_err("probe not set for driver %s\n", 917 dev_name(child_device)); 918 ret = -ENODEV; 919 } 920 return ret; 921 } 922 923 /* 924 * vmbus_remove - Remove a vmbus device 925 */ 926 static void vmbus_remove(struct device *child_device) 927 { 928 struct hv_driver *drv; 929 struct hv_device *dev = device_to_hv_device(child_device); 930 931 if (child_device->driver) { 932 drv = drv_to_hv_drv(child_device->driver); 933 if (drv->remove) 934 drv->remove(dev); 935 } 936 } 937 938 /* 939 * vmbus_shutdown - Shutdown a vmbus device 940 */ 941 static void vmbus_shutdown(struct device *child_device) 942 { 943 struct hv_driver *drv; 944 struct hv_device *dev = device_to_hv_device(child_device); 945 946 947 /* The device may not be attached yet */ 948 if (!child_device->driver) 949 return; 950 951 drv = drv_to_hv_drv(child_device->driver); 952 953 if (drv->shutdown) 954 drv->shutdown(dev); 955 } 956 957 #ifdef CONFIG_PM_SLEEP 958 /* 959 * vmbus_suspend - Suspend a vmbus device 960 */ 961 static int vmbus_suspend(struct device *child_device) 962 { 963 struct hv_driver *drv; 964 struct hv_device *dev = device_to_hv_device(child_device); 965 966 /* The device may not be attached yet */ 967 if (!child_device->driver) 968 return 0; 969 970 drv = drv_to_hv_drv(child_device->driver); 971 if (!drv->suspend) 972 return -EOPNOTSUPP; 973 974 return drv->suspend(dev); 975 } 976 977 /* 978 * vmbus_resume - Resume a vmbus device 979 */ 980 static int vmbus_resume(struct device *child_device) 981 { 982 struct hv_driver *drv; 983 struct hv_device *dev = device_to_hv_device(child_device); 984 985 /* The device may not be attached yet */ 986 if (!child_device->driver) 987 return 0; 988 989 drv = drv_to_hv_drv(child_device->driver); 990 if (!drv->resume) 991 return -EOPNOTSUPP; 992 993 return drv->resume(dev); 994 } 995 #else 996 #define vmbus_suspend NULL 997 #define vmbus_resume NULL 998 #endif /* CONFIG_PM_SLEEP */ 999 1000 /* 1001 * vmbus_device_release - Final callback release of the vmbus child device 1002 */ 1003 static void vmbus_device_release(struct device *device) 1004 { 1005 struct hv_device *hv_dev = device_to_hv_device(device); 1006 struct vmbus_channel *channel = hv_dev->channel; 1007 1008 hv_debug_rm_dev_dir(hv_dev); 1009 1010 mutex_lock(&vmbus_connection.channel_mutex); 1011 hv_process_channel_removal(channel); 1012 mutex_unlock(&vmbus_connection.channel_mutex); 1013 kfree(hv_dev); 1014 } 1015 1016 /* 1017 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm. 1018 * 1019 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we 1020 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there 1021 * is no way to wake up a Generation-2 VM. 1022 * 1023 * The other 4 ops are for hibernation. 1024 */ 1025 1026 static const struct dev_pm_ops vmbus_pm = { 1027 .suspend_noirq = NULL, 1028 .resume_noirq = NULL, 1029 .freeze_noirq = vmbus_suspend, 1030 .thaw_noirq = vmbus_resume, 1031 .poweroff_noirq = vmbus_suspend, 1032 .restore_noirq = vmbus_resume, 1033 }; 1034 1035 /* The one and only one */ 1036 static struct bus_type hv_bus = { 1037 .name = "vmbus", 1038 .match = vmbus_match, 1039 .shutdown = vmbus_shutdown, 1040 .remove = vmbus_remove, 1041 .probe = vmbus_probe, 1042 .uevent = vmbus_uevent, 1043 .dev_groups = vmbus_dev_groups, 1044 .drv_groups = vmbus_drv_groups, 1045 .bus_groups = vmbus_bus_groups, 1046 .pm = &vmbus_pm, 1047 }; 1048 1049 struct onmessage_work_context { 1050 struct work_struct work; 1051 struct { 1052 struct hv_message_header header; 1053 u8 payload[]; 1054 } msg; 1055 }; 1056 1057 static void vmbus_onmessage_work(struct work_struct *work) 1058 { 1059 struct onmessage_work_context *ctx; 1060 1061 /* Do not process messages if we're in DISCONNECTED state */ 1062 if (vmbus_connection.conn_state == DISCONNECTED) 1063 return; 1064 1065 ctx = container_of(work, struct onmessage_work_context, 1066 work); 1067 vmbus_onmessage((struct vmbus_channel_message_header *) 1068 &ctx->msg.payload); 1069 kfree(ctx); 1070 } 1071 1072 void vmbus_on_msg_dpc(unsigned long data) 1073 { 1074 struct hv_per_cpu_context *hv_cpu = (void *)data; 1075 void *page_addr = hv_cpu->synic_message_page; 1076 struct hv_message msg_copy, *msg = (struct hv_message *)page_addr + 1077 VMBUS_MESSAGE_SINT; 1078 struct vmbus_channel_message_header *hdr; 1079 enum vmbus_channel_message_type msgtype; 1080 const struct vmbus_channel_message_table_entry *entry; 1081 struct onmessage_work_context *ctx; 1082 __u8 payload_size; 1083 u32 message_type; 1084 1085 /* 1086 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as 1087 * it is being used in 'struct vmbus_channel_message_header' definition 1088 * which is supposed to match hypervisor ABI. 1089 */ 1090 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32)); 1091 1092 /* 1093 * Since the message is in memory shared with the host, an erroneous or 1094 * malicious Hyper-V could modify the message while vmbus_on_msg_dpc() 1095 * or individual message handlers are executing; to prevent this, copy 1096 * the message into private memory. 1097 */ 1098 memcpy(&msg_copy, msg, sizeof(struct hv_message)); 1099 1100 message_type = msg_copy.header.message_type; 1101 if (message_type == HVMSG_NONE) 1102 /* no msg */ 1103 return; 1104 1105 hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload; 1106 msgtype = hdr->msgtype; 1107 1108 trace_vmbus_on_msg_dpc(hdr); 1109 1110 if (msgtype >= CHANNELMSG_COUNT) { 1111 WARN_ONCE(1, "unknown msgtype=%d\n", msgtype); 1112 goto msg_handled; 1113 } 1114 1115 payload_size = msg_copy.header.payload_size; 1116 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) { 1117 WARN_ONCE(1, "payload size is too large (%d)\n", payload_size); 1118 goto msg_handled; 1119 } 1120 1121 entry = &channel_message_table[msgtype]; 1122 1123 if (!entry->message_handler) 1124 goto msg_handled; 1125 1126 if (payload_size < entry->min_payload_len) { 1127 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size); 1128 goto msg_handled; 1129 } 1130 1131 if (entry->handler_type == VMHT_BLOCKING) { 1132 ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC); 1133 if (ctx == NULL) 1134 return; 1135 1136 INIT_WORK(&ctx->work, vmbus_onmessage_work); 1137 memcpy(&ctx->msg, &msg_copy, sizeof(msg->header) + payload_size); 1138 1139 /* 1140 * The host can generate a rescind message while we 1141 * may still be handling the original offer. We deal with 1142 * this condition by relying on the synchronization provided 1143 * by offer_in_progress and by channel_mutex. See also the 1144 * inline comments in vmbus_onoffer_rescind(). 1145 */ 1146 switch (msgtype) { 1147 case CHANNELMSG_RESCIND_CHANNELOFFER: 1148 /* 1149 * If we are handling the rescind message; 1150 * schedule the work on the global work queue. 1151 * 1152 * The OFFER message and the RESCIND message should 1153 * not be handled by the same serialized work queue, 1154 * because the OFFER handler may call vmbus_open(), 1155 * which tries to open the channel by sending an 1156 * OPEN_CHANNEL message to the host and waits for 1157 * the host's response; however, if the host has 1158 * rescinded the channel before it receives the 1159 * OPEN_CHANNEL message, the host just silently 1160 * ignores the OPEN_CHANNEL message; as a result, 1161 * the guest's OFFER handler hangs for ever, if we 1162 * handle the RESCIND message in the same serialized 1163 * work queue: the RESCIND handler can not start to 1164 * run before the OFFER handler finishes. 1165 */ 1166 schedule_work(&ctx->work); 1167 break; 1168 1169 case CHANNELMSG_OFFERCHANNEL: 1170 /* 1171 * The host sends the offer message of a given channel 1172 * before sending the rescind message of the same 1173 * channel. These messages are sent to the guest's 1174 * connect CPU; the guest then starts processing them 1175 * in the tasklet handler on this CPU: 1176 * 1177 * VMBUS_CONNECT_CPU 1178 * 1179 * [vmbus_on_msg_dpc()] 1180 * atomic_inc() // CHANNELMSG_OFFERCHANNEL 1181 * queue_work() 1182 * ... 1183 * [vmbus_on_msg_dpc()] 1184 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER 1185 * 1186 * We rely on the memory-ordering properties of the 1187 * queue_work() and schedule_work() primitives, which 1188 * guarantee that the atomic increment will be visible 1189 * to the CPUs which will execute the offer & rescind 1190 * works by the time these works will start execution. 1191 */ 1192 atomic_inc(&vmbus_connection.offer_in_progress); 1193 fallthrough; 1194 1195 default: 1196 queue_work(vmbus_connection.work_queue, &ctx->work); 1197 } 1198 } else 1199 entry->message_handler(hdr); 1200 1201 msg_handled: 1202 vmbus_signal_eom(msg, message_type); 1203 } 1204 1205 #ifdef CONFIG_PM_SLEEP 1206 /* 1207 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for 1208 * hibernation, because hv_sock connections can not persist across hibernation. 1209 */ 1210 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel) 1211 { 1212 struct onmessage_work_context *ctx; 1213 struct vmbus_channel_rescind_offer *rescind; 1214 1215 WARN_ON(!is_hvsock_channel(channel)); 1216 1217 /* 1218 * Allocation size is small and the allocation should really not fail, 1219 * otherwise the state of the hv_sock connections ends up in limbo. 1220 */ 1221 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind), 1222 GFP_KERNEL | __GFP_NOFAIL); 1223 1224 /* 1225 * So far, these are not really used by Linux. Just set them to the 1226 * reasonable values conforming to the definitions of the fields. 1227 */ 1228 ctx->msg.header.message_type = 1; 1229 ctx->msg.header.payload_size = sizeof(*rescind); 1230 1231 /* These values are actually used by Linux. */ 1232 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload; 1233 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER; 1234 rescind->child_relid = channel->offermsg.child_relid; 1235 1236 INIT_WORK(&ctx->work, vmbus_onmessage_work); 1237 1238 queue_work(vmbus_connection.work_queue, &ctx->work); 1239 } 1240 #endif /* CONFIG_PM_SLEEP */ 1241 1242 /* 1243 * Schedule all channels with events pending 1244 */ 1245 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) 1246 { 1247 unsigned long *recv_int_page; 1248 u32 maxbits, relid; 1249 1250 if (vmbus_proto_version < VERSION_WIN8) { 1251 maxbits = MAX_NUM_CHANNELS_SUPPORTED; 1252 recv_int_page = vmbus_connection.recv_int_page; 1253 } else { 1254 /* 1255 * When the host is win8 and beyond, the event page 1256 * can be directly checked to get the id of the channel 1257 * that has the interrupt pending. 1258 */ 1259 void *page_addr = hv_cpu->synic_event_page; 1260 union hv_synic_event_flags *event 1261 = (union hv_synic_event_flags *)page_addr + 1262 VMBUS_MESSAGE_SINT; 1263 1264 maxbits = HV_EVENT_FLAGS_COUNT; 1265 recv_int_page = event->flags; 1266 } 1267 1268 if (unlikely(!recv_int_page)) 1269 return; 1270 1271 for_each_set_bit(relid, recv_int_page, maxbits) { 1272 void (*callback_fn)(void *context); 1273 struct vmbus_channel *channel; 1274 1275 if (!sync_test_and_clear_bit(relid, recv_int_page)) 1276 continue; 1277 1278 /* Special case - vmbus channel protocol msg */ 1279 if (relid == 0) 1280 continue; 1281 1282 /* 1283 * Pairs with the kfree_rcu() in vmbus_chan_release(). 1284 * Guarantees that the channel data structure doesn't 1285 * get freed while the channel pointer below is being 1286 * dereferenced. 1287 */ 1288 rcu_read_lock(); 1289 1290 /* Find channel based on relid */ 1291 channel = relid2channel(relid); 1292 if (channel == NULL) 1293 goto sched_unlock_rcu; 1294 1295 if (channel->rescind) 1296 goto sched_unlock_rcu; 1297 1298 /* 1299 * Make sure that the ring buffer data structure doesn't get 1300 * freed while we dereference the ring buffer pointer. Test 1301 * for the channel's onchannel_callback being NULL within a 1302 * sched_lock critical section. See also the inline comments 1303 * in vmbus_reset_channel_cb(). 1304 */ 1305 spin_lock(&channel->sched_lock); 1306 1307 callback_fn = channel->onchannel_callback; 1308 if (unlikely(callback_fn == NULL)) 1309 goto sched_unlock; 1310 1311 trace_vmbus_chan_sched(channel); 1312 1313 ++channel->interrupts; 1314 1315 switch (channel->callback_mode) { 1316 case HV_CALL_ISR: 1317 (*callback_fn)(channel->channel_callback_context); 1318 break; 1319 1320 case HV_CALL_BATCHED: 1321 hv_begin_read(&channel->inbound); 1322 fallthrough; 1323 case HV_CALL_DIRECT: 1324 tasklet_schedule(&channel->callback_event); 1325 } 1326 1327 sched_unlock: 1328 spin_unlock(&channel->sched_lock); 1329 sched_unlock_rcu: 1330 rcu_read_unlock(); 1331 } 1332 } 1333 1334 static void vmbus_isr(void) 1335 { 1336 struct hv_per_cpu_context *hv_cpu 1337 = this_cpu_ptr(hv_context.cpu_context); 1338 void *page_addr = hv_cpu->synic_event_page; 1339 struct hv_message *msg; 1340 union hv_synic_event_flags *event; 1341 bool handled = false; 1342 1343 if (unlikely(page_addr == NULL)) 1344 return; 1345 1346 event = (union hv_synic_event_flags *)page_addr + 1347 VMBUS_MESSAGE_SINT; 1348 /* 1349 * Check for events before checking for messages. This is the order 1350 * in which events and messages are checked in Windows guests on 1351 * Hyper-V, and the Windows team suggested we do the same. 1352 */ 1353 1354 if ((vmbus_proto_version == VERSION_WS2008) || 1355 (vmbus_proto_version == VERSION_WIN7)) { 1356 1357 /* Since we are a child, we only need to check bit 0 */ 1358 if (sync_test_and_clear_bit(0, event->flags)) 1359 handled = true; 1360 } else { 1361 /* 1362 * Our host is win8 or above. The signaling mechanism 1363 * has changed and we can directly look at the event page. 1364 * If bit n is set then we have an interrup on the channel 1365 * whose id is n. 1366 */ 1367 handled = true; 1368 } 1369 1370 if (handled) 1371 vmbus_chan_sched(hv_cpu); 1372 1373 page_addr = hv_cpu->synic_message_page; 1374 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; 1375 1376 /* Check if there are actual msgs to be processed */ 1377 if (msg->header.message_type != HVMSG_NONE) { 1378 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) { 1379 hv_stimer0_isr(); 1380 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED); 1381 } else 1382 tasklet_schedule(&hv_cpu->msg_dpc); 1383 } 1384 1385 add_interrupt_randomness(vmbus_interrupt); 1386 } 1387 1388 static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) 1389 { 1390 vmbus_isr(); 1391 return IRQ_HANDLED; 1392 } 1393 1394 /* 1395 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg 1396 * buffer and call into Hyper-V to transfer the data. 1397 */ 1398 static void hv_kmsg_dump(struct kmsg_dumper *dumper, 1399 enum kmsg_dump_reason reason) 1400 { 1401 struct kmsg_dump_iter iter; 1402 size_t bytes_written; 1403 1404 /* We are only interested in panics. */ 1405 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg)) 1406 return; 1407 1408 /* 1409 * Write dump contents to the page. No need to synchronize; panic should 1410 * be single-threaded. 1411 */ 1412 kmsg_dump_rewind(&iter); 1413 kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE, 1414 &bytes_written); 1415 if (!bytes_written) 1416 return; 1417 /* 1418 * P3 to contain the physical address of the panic page & P4 to 1419 * contain the size of the panic data in that page. Rest of the 1420 * registers are no-op when the NOTIFY_MSG flag is set. 1421 */ 1422 hv_set_register(HV_REGISTER_CRASH_P0, 0); 1423 hv_set_register(HV_REGISTER_CRASH_P1, 0); 1424 hv_set_register(HV_REGISTER_CRASH_P2, 0); 1425 hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page)); 1426 hv_set_register(HV_REGISTER_CRASH_P4, bytes_written); 1427 1428 /* 1429 * Let Hyper-V know there is crash data available along with 1430 * the panic message. 1431 */ 1432 hv_set_register(HV_REGISTER_CRASH_CTL, 1433 (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG)); 1434 } 1435 1436 static struct kmsg_dumper hv_kmsg_dumper = { 1437 .dump = hv_kmsg_dump, 1438 }; 1439 1440 static void hv_kmsg_dump_register(void) 1441 { 1442 int ret; 1443 1444 hv_panic_page = hv_alloc_hyperv_zeroed_page(); 1445 if (!hv_panic_page) { 1446 pr_err("Hyper-V: panic message page memory allocation failed\n"); 1447 return; 1448 } 1449 1450 ret = kmsg_dump_register(&hv_kmsg_dumper); 1451 if (ret) { 1452 pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret); 1453 hv_free_hyperv_page((unsigned long)hv_panic_page); 1454 hv_panic_page = NULL; 1455 } 1456 } 1457 1458 static struct ctl_table_header *hv_ctl_table_hdr; 1459 1460 /* 1461 * sysctl option to allow the user to control whether kmsg data should be 1462 * reported to Hyper-V on panic. 1463 */ 1464 static struct ctl_table hv_ctl_table[] = { 1465 { 1466 .procname = "hyperv_record_panic_msg", 1467 .data = &sysctl_record_panic_msg, 1468 .maxlen = sizeof(int), 1469 .mode = 0644, 1470 .proc_handler = proc_dointvec_minmax, 1471 .extra1 = SYSCTL_ZERO, 1472 .extra2 = SYSCTL_ONE 1473 }, 1474 {} 1475 }; 1476 1477 static struct ctl_table hv_root_table[] = { 1478 { 1479 .procname = "kernel", 1480 .mode = 0555, 1481 .child = hv_ctl_table 1482 }, 1483 {} 1484 }; 1485 1486 /* 1487 * vmbus_bus_init -Main vmbus driver initialization routine. 1488 * 1489 * Here, we 1490 * - initialize the vmbus driver context 1491 * - invoke the vmbus hv main init routine 1492 * - retrieve the channel offers 1493 */ 1494 static int vmbus_bus_init(void) 1495 { 1496 int ret; 1497 1498 ret = hv_init(); 1499 if (ret != 0) { 1500 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret); 1501 return ret; 1502 } 1503 1504 ret = bus_register(&hv_bus); 1505 if (ret) 1506 return ret; 1507 1508 /* 1509 * VMbus interrupts are best modeled as per-cpu interrupts. If 1510 * on an architecture with support for per-cpu IRQs (e.g. ARM64), 1511 * allocate a per-cpu IRQ using standard Linux kernel functionality. 1512 * If not on such an architecture (e.g., x86/x64), then rely on 1513 * code in the arch-specific portion of the code tree to connect 1514 * the VMbus interrupt handler. 1515 */ 1516 1517 if (vmbus_irq == -1) { 1518 hv_setup_vmbus_handler(vmbus_isr); 1519 } else { 1520 vmbus_evt = alloc_percpu(long); 1521 ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr, 1522 "Hyper-V VMbus", vmbus_evt); 1523 if (ret) { 1524 pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d", 1525 vmbus_irq, ret); 1526 free_percpu(vmbus_evt); 1527 goto err_setup; 1528 } 1529 } 1530 1531 ret = hv_synic_alloc(); 1532 if (ret) 1533 goto err_alloc; 1534 1535 /* 1536 * Initialize the per-cpu interrupt state and stimer state. 1537 * Then connect to the host. 1538 */ 1539 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online", 1540 hv_synic_init, hv_synic_cleanup); 1541 if (ret < 0) 1542 goto err_cpuhp; 1543 hyperv_cpuhp_online = ret; 1544 1545 ret = vmbus_connect(); 1546 if (ret) 1547 goto err_connect; 1548 1549 /* 1550 * Only register if the crash MSRs are available 1551 */ 1552 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { 1553 u64 hyperv_crash_ctl; 1554 /* 1555 * Sysctl registration is not fatal, since by default 1556 * reporting is enabled. 1557 */ 1558 hv_ctl_table_hdr = register_sysctl_table(hv_root_table); 1559 if (!hv_ctl_table_hdr) 1560 pr_err("Hyper-V: sysctl table register error"); 1561 1562 /* 1563 * Register for panic kmsg callback only if the right 1564 * capability is supported by the hypervisor. 1565 */ 1566 hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL); 1567 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) 1568 hv_kmsg_dump_register(); 1569 1570 register_die_notifier(&hyperv_die_block); 1571 } 1572 1573 /* 1574 * Always register the panic notifier because we need to unload 1575 * the VMbus channel connection to prevent any VMbus 1576 * activity after the VM panics. 1577 */ 1578 atomic_notifier_chain_register(&panic_notifier_list, 1579 &hyperv_panic_block); 1580 1581 vmbus_request_offers(); 1582 1583 return 0; 1584 1585 err_connect: 1586 cpuhp_remove_state(hyperv_cpuhp_online); 1587 err_cpuhp: 1588 hv_synic_free(); 1589 err_alloc: 1590 if (vmbus_irq == -1) { 1591 hv_remove_vmbus_handler(); 1592 } else { 1593 free_percpu_irq(vmbus_irq, vmbus_evt); 1594 free_percpu(vmbus_evt); 1595 } 1596 err_setup: 1597 bus_unregister(&hv_bus); 1598 unregister_sysctl_table(hv_ctl_table_hdr); 1599 hv_ctl_table_hdr = NULL; 1600 return ret; 1601 } 1602 1603 /** 1604 * __vmbus_child_driver_register() - Register a vmbus's driver 1605 * @hv_driver: Pointer to driver structure you want to register 1606 * @owner: owner module of the drv 1607 * @mod_name: module name string 1608 * 1609 * Registers the given driver with Linux through the 'driver_register()' call 1610 * and sets up the hyper-v vmbus handling for this driver. 1611 * It will return the state of the 'driver_register()' call. 1612 * 1613 */ 1614 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name) 1615 { 1616 int ret; 1617 1618 pr_info("registering driver %s\n", hv_driver->name); 1619 1620 ret = vmbus_exists(); 1621 if (ret < 0) 1622 return ret; 1623 1624 hv_driver->driver.name = hv_driver->name; 1625 hv_driver->driver.owner = owner; 1626 hv_driver->driver.mod_name = mod_name; 1627 hv_driver->driver.bus = &hv_bus; 1628 1629 spin_lock_init(&hv_driver->dynids.lock); 1630 INIT_LIST_HEAD(&hv_driver->dynids.list); 1631 1632 ret = driver_register(&hv_driver->driver); 1633 1634 return ret; 1635 } 1636 EXPORT_SYMBOL_GPL(__vmbus_driver_register); 1637 1638 /** 1639 * vmbus_driver_unregister() - Unregister a vmbus's driver 1640 * @hv_driver: Pointer to driver structure you want to 1641 * un-register 1642 * 1643 * Un-register the given driver that was previous registered with a call to 1644 * vmbus_driver_register() 1645 */ 1646 void vmbus_driver_unregister(struct hv_driver *hv_driver) 1647 { 1648 pr_info("unregistering driver %s\n", hv_driver->name); 1649 1650 if (!vmbus_exists()) { 1651 driver_unregister(&hv_driver->driver); 1652 vmbus_free_dynids(hv_driver); 1653 } 1654 } 1655 EXPORT_SYMBOL_GPL(vmbus_driver_unregister); 1656 1657 1658 /* 1659 * Called when last reference to channel is gone. 1660 */ 1661 static void vmbus_chan_release(struct kobject *kobj) 1662 { 1663 struct vmbus_channel *channel 1664 = container_of(kobj, struct vmbus_channel, kobj); 1665 1666 kfree_rcu(channel, rcu); 1667 } 1668 1669 struct vmbus_chan_attribute { 1670 struct attribute attr; 1671 ssize_t (*show)(struct vmbus_channel *chan, char *buf); 1672 ssize_t (*store)(struct vmbus_channel *chan, 1673 const char *buf, size_t count); 1674 }; 1675 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \ 1676 struct vmbus_chan_attribute chan_attr_##_name \ 1677 = __ATTR(_name, _mode, _show, _store) 1678 #define VMBUS_CHAN_ATTR_RW(_name) \ 1679 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name) 1680 #define VMBUS_CHAN_ATTR_RO(_name) \ 1681 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name) 1682 #define VMBUS_CHAN_ATTR_WO(_name) \ 1683 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name) 1684 1685 static ssize_t vmbus_chan_attr_show(struct kobject *kobj, 1686 struct attribute *attr, char *buf) 1687 { 1688 const struct vmbus_chan_attribute *attribute 1689 = container_of(attr, struct vmbus_chan_attribute, attr); 1690 struct vmbus_channel *chan 1691 = container_of(kobj, struct vmbus_channel, kobj); 1692 1693 if (!attribute->show) 1694 return -EIO; 1695 1696 return attribute->show(chan, buf); 1697 } 1698 1699 static ssize_t vmbus_chan_attr_store(struct kobject *kobj, 1700 struct attribute *attr, const char *buf, 1701 size_t count) 1702 { 1703 const struct vmbus_chan_attribute *attribute 1704 = container_of(attr, struct vmbus_chan_attribute, attr); 1705 struct vmbus_channel *chan 1706 = container_of(kobj, struct vmbus_channel, kobj); 1707 1708 if (!attribute->store) 1709 return -EIO; 1710 1711 return attribute->store(chan, buf, count); 1712 } 1713 1714 static const struct sysfs_ops vmbus_chan_sysfs_ops = { 1715 .show = vmbus_chan_attr_show, 1716 .store = vmbus_chan_attr_store, 1717 }; 1718 1719 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf) 1720 { 1721 struct hv_ring_buffer_info *rbi = &channel->outbound; 1722 ssize_t ret; 1723 1724 mutex_lock(&rbi->ring_buffer_mutex); 1725 if (!rbi->ring_buffer) { 1726 mutex_unlock(&rbi->ring_buffer_mutex); 1727 return -EINVAL; 1728 } 1729 1730 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); 1731 mutex_unlock(&rbi->ring_buffer_mutex); 1732 return ret; 1733 } 1734 static VMBUS_CHAN_ATTR_RO(out_mask); 1735 1736 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf) 1737 { 1738 struct hv_ring_buffer_info *rbi = &channel->inbound; 1739 ssize_t ret; 1740 1741 mutex_lock(&rbi->ring_buffer_mutex); 1742 if (!rbi->ring_buffer) { 1743 mutex_unlock(&rbi->ring_buffer_mutex); 1744 return -EINVAL; 1745 } 1746 1747 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); 1748 mutex_unlock(&rbi->ring_buffer_mutex); 1749 return ret; 1750 } 1751 static VMBUS_CHAN_ATTR_RO(in_mask); 1752 1753 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf) 1754 { 1755 struct hv_ring_buffer_info *rbi = &channel->inbound; 1756 ssize_t ret; 1757 1758 mutex_lock(&rbi->ring_buffer_mutex); 1759 if (!rbi->ring_buffer) { 1760 mutex_unlock(&rbi->ring_buffer_mutex); 1761 return -EINVAL; 1762 } 1763 1764 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi)); 1765 mutex_unlock(&rbi->ring_buffer_mutex); 1766 return ret; 1767 } 1768 static VMBUS_CHAN_ATTR_RO(read_avail); 1769 1770 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf) 1771 { 1772 struct hv_ring_buffer_info *rbi = &channel->outbound; 1773 ssize_t ret; 1774 1775 mutex_lock(&rbi->ring_buffer_mutex); 1776 if (!rbi->ring_buffer) { 1777 mutex_unlock(&rbi->ring_buffer_mutex); 1778 return -EINVAL; 1779 } 1780 1781 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi)); 1782 mutex_unlock(&rbi->ring_buffer_mutex); 1783 return ret; 1784 } 1785 static VMBUS_CHAN_ATTR_RO(write_avail); 1786 1787 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf) 1788 { 1789 return sprintf(buf, "%u\n", channel->target_cpu); 1790 } 1791 static ssize_t target_cpu_store(struct vmbus_channel *channel, 1792 const char *buf, size_t count) 1793 { 1794 u32 target_cpu, origin_cpu; 1795 ssize_t ret = count; 1796 1797 if (vmbus_proto_version < VERSION_WIN10_V4_1) 1798 return -EIO; 1799 1800 if (sscanf(buf, "%uu", &target_cpu) != 1) 1801 return -EIO; 1802 1803 /* Validate target_cpu for the cpumask_test_cpu() operation below. */ 1804 if (target_cpu >= nr_cpumask_bits) 1805 return -EINVAL; 1806 1807 /* No CPUs should come up or down during this. */ 1808 cpus_read_lock(); 1809 1810 if (!cpu_online(target_cpu)) { 1811 cpus_read_unlock(); 1812 return -EINVAL; 1813 } 1814 1815 /* 1816 * Synchronizes target_cpu_store() and channel closure: 1817 * 1818 * { Initially: state = CHANNEL_OPENED } 1819 * 1820 * CPU1 CPU2 1821 * 1822 * [target_cpu_store()] [vmbus_disconnect_ring()] 1823 * 1824 * LOCK channel_mutex LOCK channel_mutex 1825 * LOAD r1 = state LOAD r2 = state 1826 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED) 1827 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN 1828 * [...] SEND CLOSECHANNEL 1829 * UNLOCK channel_mutex UNLOCK channel_mutex 1830 * 1831 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes 1832 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND 1833 * 1834 * Note. The host processes the channel messages "sequentially", in 1835 * the order in which they are received on a per-partition basis. 1836 */ 1837 mutex_lock(&vmbus_connection.channel_mutex); 1838 1839 /* 1840 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels; 1841 * avoid sending the message and fail here for such channels. 1842 */ 1843 if (channel->state != CHANNEL_OPENED_STATE) { 1844 ret = -EIO; 1845 goto cpu_store_unlock; 1846 } 1847 1848 origin_cpu = channel->target_cpu; 1849 if (target_cpu == origin_cpu) 1850 goto cpu_store_unlock; 1851 1852 if (vmbus_send_modifychannel(channel, 1853 hv_cpu_number_to_vp_number(target_cpu))) { 1854 ret = -EIO; 1855 goto cpu_store_unlock; 1856 } 1857 1858 /* 1859 * For version before VERSION_WIN10_V5_3, the following warning holds: 1860 * 1861 * Warning. At this point, there is *no* guarantee that the host will 1862 * have successfully processed the vmbus_send_modifychannel() request. 1863 * See the header comment of vmbus_send_modifychannel() for more info. 1864 * 1865 * Lags in the processing of the above vmbus_send_modifychannel() can 1866 * result in missed interrupts if the "old" target CPU is taken offline 1867 * before Hyper-V starts sending interrupts to the "new" target CPU. 1868 * But apart from this offlining scenario, the code tolerates such 1869 * lags. It will function correctly even if a channel interrupt comes 1870 * in on a CPU that is different from the channel target_cpu value. 1871 */ 1872 1873 channel->target_cpu = target_cpu; 1874 1875 /* See init_vp_index(). */ 1876 if (hv_is_perf_channel(channel)) 1877 hv_update_allocated_cpus(origin_cpu, target_cpu); 1878 1879 /* Currently set only for storvsc channels. */ 1880 if (channel->change_target_cpu_callback) { 1881 (*channel->change_target_cpu_callback)(channel, 1882 origin_cpu, target_cpu); 1883 } 1884 1885 cpu_store_unlock: 1886 mutex_unlock(&vmbus_connection.channel_mutex); 1887 cpus_read_unlock(); 1888 return ret; 1889 } 1890 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store); 1891 1892 static ssize_t channel_pending_show(struct vmbus_channel *channel, 1893 char *buf) 1894 { 1895 return sprintf(buf, "%d\n", 1896 channel_pending(channel, 1897 vmbus_connection.monitor_pages[1])); 1898 } 1899 static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL); 1900 1901 static ssize_t channel_latency_show(struct vmbus_channel *channel, 1902 char *buf) 1903 { 1904 return sprintf(buf, "%d\n", 1905 channel_latency(channel, 1906 vmbus_connection.monitor_pages[1])); 1907 } 1908 static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL); 1909 1910 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf) 1911 { 1912 return sprintf(buf, "%llu\n", channel->interrupts); 1913 } 1914 static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL); 1915 1916 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf) 1917 { 1918 return sprintf(buf, "%llu\n", channel->sig_events); 1919 } 1920 static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL); 1921 1922 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel, 1923 char *buf) 1924 { 1925 return sprintf(buf, "%llu\n", 1926 (unsigned long long)channel->intr_in_full); 1927 } 1928 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL); 1929 1930 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel, 1931 char *buf) 1932 { 1933 return sprintf(buf, "%llu\n", 1934 (unsigned long long)channel->intr_out_empty); 1935 } 1936 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL); 1937 1938 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel, 1939 char *buf) 1940 { 1941 return sprintf(buf, "%llu\n", 1942 (unsigned long long)channel->out_full_first); 1943 } 1944 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL); 1945 1946 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel, 1947 char *buf) 1948 { 1949 return sprintf(buf, "%llu\n", 1950 (unsigned long long)channel->out_full_total); 1951 } 1952 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL); 1953 1954 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel, 1955 char *buf) 1956 { 1957 return sprintf(buf, "%u\n", channel->offermsg.monitorid); 1958 } 1959 static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL); 1960 1961 static ssize_t subchannel_id_show(struct vmbus_channel *channel, 1962 char *buf) 1963 { 1964 return sprintf(buf, "%u\n", 1965 channel->offermsg.offer.sub_channel_index); 1966 } 1967 static VMBUS_CHAN_ATTR_RO(subchannel_id); 1968 1969 static struct attribute *vmbus_chan_attrs[] = { 1970 &chan_attr_out_mask.attr, 1971 &chan_attr_in_mask.attr, 1972 &chan_attr_read_avail.attr, 1973 &chan_attr_write_avail.attr, 1974 &chan_attr_cpu.attr, 1975 &chan_attr_pending.attr, 1976 &chan_attr_latency.attr, 1977 &chan_attr_interrupts.attr, 1978 &chan_attr_events.attr, 1979 &chan_attr_intr_in_full.attr, 1980 &chan_attr_intr_out_empty.attr, 1981 &chan_attr_out_full_first.attr, 1982 &chan_attr_out_full_total.attr, 1983 &chan_attr_monitor_id.attr, 1984 &chan_attr_subchannel_id.attr, 1985 NULL 1986 }; 1987 1988 /* 1989 * Channel-level attribute_group callback function. Returns the permission for 1990 * each attribute, and returns 0 if an attribute is not visible. 1991 */ 1992 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, 1993 struct attribute *attr, int idx) 1994 { 1995 const struct vmbus_channel *channel = 1996 container_of(kobj, struct vmbus_channel, kobj); 1997 1998 /* Hide the monitor attributes if the monitor mechanism is not used. */ 1999 if (!channel->offermsg.monitor_allocated && 2000 (attr == &chan_attr_pending.attr || 2001 attr == &chan_attr_latency.attr || 2002 attr == &chan_attr_monitor_id.attr)) 2003 return 0; 2004 2005 return attr->mode; 2006 } 2007 2008 static struct attribute_group vmbus_chan_group = { 2009 .attrs = vmbus_chan_attrs, 2010 .is_visible = vmbus_chan_attr_is_visible 2011 }; 2012 2013 static struct kobj_type vmbus_chan_ktype = { 2014 .sysfs_ops = &vmbus_chan_sysfs_ops, 2015 .release = vmbus_chan_release, 2016 }; 2017 2018 /* 2019 * vmbus_add_channel_kobj - setup a sub-directory under device/channels 2020 */ 2021 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel) 2022 { 2023 const struct device *device = &dev->device; 2024 struct kobject *kobj = &channel->kobj; 2025 u32 relid = channel->offermsg.child_relid; 2026 int ret; 2027 2028 kobj->kset = dev->channels_kset; 2029 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL, 2030 "%u", relid); 2031 if (ret) { 2032 kobject_put(kobj); 2033 return ret; 2034 } 2035 2036 ret = sysfs_create_group(kobj, &vmbus_chan_group); 2037 2038 if (ret) { 2039 /* 2040 * The calling functions' error handling paths will cleanup the 2041 * empty channel directory. 2042 */ 2043 kobject_put(kobj); 2044 dev_err(device, "Unable to set up channel sysfs files\n"); 2045 return ret; 2046 } 2047 2048 kobject_uevent(kobj, KOBJ_ADD); 2049 2050 return 0; 2051 } 2052 2053 /* 2054 * vmbus_remove_channel_attr_group - remove the channel's attribute group 2055 */ 2056 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel) 2057 { 2058 sysfs_remove_group(&channel->kobj, &vmbus_chan_group); 2059 } 2060 2061 /* 2062 * vmbus_device_create - Creates and registers a new child device 2063 * on the vmbus. 2064 */ 2065 struct hv_device *vmbus_device_create(const guid_t *type, 2066 const guid_t *instance, 2067 struct vmbus_channel *channel) 2068 { 2069 struct hv_device *child_device_obj; 2070 2071 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL); 2072 if (!child_device_obj) { 2073 pr_err("Unable to allocate device object for child device\n"); 2074 return NULL; 2075 } 2076 2077 child_device_obj->channel = channel; 2078 guid_copy(&child_device_obj->dev_type, type); 2079 guid_copy(&child_device_obj->dev_instance, instance); 2080 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */ 2081 2082 return child_device_obj; 2083 } 2084 2085 /* 2086 * vmbus_device_register - Register the child device 2087 */ 2088 int vmbus_device_register(struct hv_device *child_device_obj) 2089 { 2090 struct kobject *kobj = &child_device_obj->device.kobj; 2091 int ret; 2092 2093 dev_set_name(&child_device_obj->device, "%pUl", 2094 &child_device_obj->channel->offermsg.offer.if_instance); 2095 2096 child_device_obj->device.bus = &hv_bus; 2097 child_device_obj->device.parent = &hv_acpi_dev->dev; 2098 child_device_obj->device.release = vmbus_device_release; 2099 2100 /* 2101 * Register with the LDM. This will kick off the driver/device 2102 * binding...which will eventually call vmbus_match() and vmbus_probe() 2103 */ 2104 ret = device_register(&child_device_obj->device); 2105 if (ret) { 2106 pr_err("Unable to register child device\n"); 2107 return ret; 2108 } 2109 2110 child_device_obj->channels_kset = kset_create_and_add("channels", 2111 NULL, kobj); 2112 if (!child_device_obj->channels_kset) { 2113 ret = -ENOMEM; 2114 goto err_dev_unregister; 2115 } 2116 2117 ret = vmbus_add_channel_kobj(child_device_obj, 2118 child_device_obj->channel); 2119 if (ret) { 2120 pr_err("Unable to register primary channeln"); 2121 goto err_kset_unregister; 2122 } 2123 hv_debug_add_dev_dir(child_device_obj); 2124 2125 child_device_obj->device.dma_parms = &child_device_obj->dma_parms; 2126 child_device_obj->device.dma_mask = &child_device_obj->dma_mask; 2127 dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64)); 2128 return 0; 2129 2130 err_kset_unregister: 2131 kset_unregister(child_device_obj->channels_kset); 2132 2133 err_dev_unregister: 2134 device_unregister(&child_device_obj->device); 2135 return ret; 2136 } 2137 2138 /* 2139 * vmbus_device_unregister - Remove the specified child device 2140 * from the vmbus. 2141 */ 2142 void vmbus_device_unregister(struct hv_device *device_obj) 2143 { 2144 pr_debug("child device %s unregistered\n", 2145 dev_name(&device_obj->device)); 2146 2147 kset_unregister(device_obj->channels_kset); 2148 2149 /* 2150 * Kick off the process of unregistering the device. 2151 * This will call vmbus_remove() and eventually vmbus_device_release() 2152 */ 2153 device_unregister(&device_obj->device); 2154 } 2155 2156 2157 /* 2158 * VMBUS is an acpi enumerated device. Get the information we 2159 * need from DSDT. 2160 */ 2161 #define VTPM_BASE_ADDRESS 0xfed40000 2162 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx) 2163 { 2164 resource_size_t start = 0; 2165 resource_size_t end = 0; 2166 struct resource *new_res; 2167 struct resource **old_res = &hyperv_mmio; 2168 struct resource **prev_res = NULL; 2169 struct resource r; 2170 2171 switch (res->type) { 2172 2173 /* 2174 * "Address" descriptors are for bus windows. Ignore 2175 * "memory" descriptors, which are for registers on 2176 * devices. 2177 */ 2178 case ACPI_RESOURCE_TYPE_ADDRESS32: 2179 start = res->data.address32.address.minimum; 2180 end = res->data.address32.address.maximum; 2181 break; 2182 2183 case ACPI_RESOURCE_TYPE_ADDRESS64: 2184 start = res->data.address64.address.minimum; 2185 end = res->data.address64.address.maximum; 2186 break; 2187 2188 /* 2189 * The IRQ information is needed only on ARM64, which Hyper-V 2190 * sets up in the extended format. IRQ information is present 2191 * on x86/x64 in the non-extended format but it is not used by 2192 * Linux. So don't bother checking for the non-extended format. 2193 */ 2194 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 2195 if (!acpi_dev_resource_interrupt(res, 0, &r)) { 2196 pr_err("Unable to parse Hyper-V ACPI interrupt\n"); 2197 return AE_ERROR; 2198 } 2199 /* ARM64 INTID for VMbus */ 2200 vmbus_interrupt = res->data.extended_irq.interrupts[0]; 2201 /* Linux IRQ number */ 2202 vmbus_irq = r.start; 2203 return AE_OK; 2204 2205 default: 2206 /* Unused resource type */ 2207 return AE_OK; 2208 2209 } 2210 /* 2211 * Ignore ranges that are below 1MB, as they're not 2212 * necessary or useful here. 2213 */ 2214 if (end < 0x100000) 2215 return AE_OK; 2216 2217 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC); 2218 if (!new_res) 2219 return AE_NO_MEMORY; 2220 2221 /* If this range overlaps the virtual TPM, truncate it. */ 2222 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS) 2223 end = VTPM_BASE_ADDRESS; 2224 2225 new_res->name = "hyperv mmio"; 2226 new_res->flags = IORESOURCE_MEM; 2227 new_res->start = start; 2228 new_res->end = end; 2229 2230 /* 2231 * If two ranges are adjacent, merge them. 2232 */ 2233 do { 2234 if (!*old_res) { 2235 *old_res = new_res; 2236 break; 2237 } 2238 2239 if (((*old_res)->end + 1) == new_res->start) { 2240 (*old_res)->end = new_res->end; 2241 kfree(new_res); 2242 break; 2243 } 2244 2245 if ((*old_res)->start == new_res->end + 1) { 2246 (*old_res)->start = new_res->start; 2247 kfree(new_res); 2248 break; 2249 } 2250 2251 if ((*old_res)->start > new_res->end) { 2252 new_res->sibling = *old_res; 2253 if (prev_res) 2254 (*prev_res)->sibling = new_res; 2255 *old_res = new_res; 2256 break; 2257 } 2258 2259 prev_res = old_res; 2260 old_res = &(*old_res)->sibling; 2261 2262 } while (1); 2263 2264 return AE_OK; 2265 } 2266 2267 static int vmbus_acpi_remove(struct acpi_device *device) 2268 { 2269 struct resource *cur_res; 2270 struct resource *next_res; 2271 2272 if (hyperv_mmio) { 2273 if (fb_mmio) { 2274 __release_region(hyperv_mmio, fb_mmio->start, 2275 resource_size(fb_mmio)); 2276 fb_mmio = NULL; 2277 } 2278 2279 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) { 2280 next_res = cur_res->sibling; 2281 kfree(cur_res); 2282 } 2283 } 2284 2285 return 0; 2286 } 2287 2288 static void vmbus_reserve_fb(void) 2289 { 2290 int size; 2291 /* 2292 * Make a claim for the frame buffer in the resource tree under the 2293 * first node, which will be the one below 4GB. The length seems to 2294 * be underreported, particularly in a Generation 1 VM. So start out 2295 * reserving a larger area and make it smaller until it succeeds. 2296 */ 2297 2298 if (screen_info.lfb_base) { 2299 if (efi_enabled(EFI_BOOT)) 2300 size = max_t(__u32, screen_info.lfb_size, 0x800000); 2301 else 2302 size = max_t(__u32, screen_info.lfb_size, 0x4000000); 2303 2304 for (; !fb_mmio && (size >= 0x100000); size >>= 1) { 2305 fb_mmio = __request_region(hyperv_mmio, 2306 screen_info.lfb_base, size, 2307 fb_mmio_name, 0); 2308 } 2309 } 2310 } 2311 2312 /** 2313 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range. 2314 * @new: If successful, supplied a pointer to the 2315 * allocated MMIO space. 2316 * @device_obj: Identifies the caller 2317 * @min: Minimum guest physical address of the 2318 * allocation 2319 * @max: Maximum guest physical address 2320 * @size: Size of the range to be allocated 2321 * @align: Alignment of the range to be allocated 2322 * @fb_overlap_ok: Whether this allocation can be allowed 2323 * to overlap the video frame buffer. 2324 * 2325 * This function walks the resources granted to VMBus by the 2326 * _CRS object in the ACPI namespace underneath the parent 2327 * "bridge" whether that's a root PCI bus in the Generation 1 2328 * case or a Module Device in the Generation 2 case. It then 2329 * attempts to allocate from the global MMIO pool in a way that 2330 * matches the constraints supplied in these parameters and by 2331 * that _CRS. 2332 * 2333 * Return: 0 on success, -errno on failure 2334 */ 2335 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, 2336 resource_size_t min, resource_size_t max, 2337 resource_size_t size, resource_size_t align, 2338 bool fb_overlap_ok) 2339 { 2340 struct resource *iter, *shadow; 2341 resource_size_t range_min, range_max, start; 2342 const char *dev_n = dev_name(&device_obj->device); 2343 int retval; 2344 2345 retval = -ENXIO; 2346 mutex_lock(&hyperv_mmio_lock); 2347 2348 /* 2349 * If overlaps with frame buffers are allowed, then first attempt to 2350 * make the allocation from within the reserved region. Because it 2351 * is already reserved, no shadow allocation is necessary. 2352 */ 2353 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) && 2354 !(max < fb_mmio->start)) { 2355 2356 range_min = fb_mmio->start; 2357 range_max = fb_mmio->end; 2358 start = (range_min + align - 1) & ~(align - 1); 2359 for (; start + size - 1 <= range_max; start += align) { 2360 *new = request_mem_region_exclusive(start, size, dev_n); 2361 if (*new) { 2362 retval = 0; 2363 goto exit; 2364 } 2365 } 2366 } 2367 2368 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2369 if ((iter->start >= max) || (iter->end <= min)) 2370 continue; 2371 2372 range_min = iter->start; 2373 range_max = iter->end; 2374 start = (range_min + align - 1) & ~(align - 1); 2375 for (; start + size - 1 <= range_max; start += align) { 2376 shadow = __request_region(iter, start, size, NULL, 2377 IORESOURCE_BUSY); 2378 if (!shadow) 2379 continue; 2380 2381 *new = request_mem_region_exclusive(start, size, dev_n); 2382 if (*new) { 2383 shadow->name = (char *)*new; 2384 retval = 0; 2385 goto exit; 2386 } 2387 2388 __release_region(iter, start, size); 2389 } 2390 } 2391 2392 exit: 2393 mutex_unlock(&hyperv_mmio_lock); 2394 return retval; 2395 } 2396 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); 2397 2398 /** 2399 * vmbus_free_mmio() - Free a memory-mapped I/O range. 2400 * @start: Base address of region to release. 2401 * @size: Size of the range to be allocated 2402 * 2403 * This function releases anything requested by 2404 * vmbus_mmio_allocate(). 2405 */ 2406 void vmbus_free_mmio(resource_size_t start, resource_size_t size) 2407 { 2408 struct resource *iter; 2409 2410 mutex_lock(&hyperv_mmio_lock); 2411 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2412 if ((iter->start >= start + size) || (iter->end <= start)) 2413 continue; 2414 2415 __release_region(iter, start, size); 2416 } 2417 release_mem_region(start, size); 2418 mutex_unlock(&hyperv_mmio_lock); 2419 2420 } 2421 EXPORT_SYMBOL_GPL(vmbus_free_mmio); 2422 2423 static int vmbus_acpi_add(struct acpi_device *device) 2424 { 2425 acpi_status result; 2426 int ret_val = -ENODEV; 2427 struct acpi_device *ancestor; 2428 2429 hv_acpi_dev = device; 2430 2431 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS, 2432 vmbus_walk_resources, NULL); 2433 2434 if (ACPI_FAILURE(result)) 2435 goto acpi_walk_err; 2436 /* 2437 * Some ancestor of the vmbus acpi device (Gen1 or Gen2 2438 * firmware) is the VMOD that has the mmio ranges. Get that. 2439 */ 2440 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) { 2441 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS, 2442 vmbus_walk_resources, NULL); 2443 2444 if (ACPI_FAILURE(result)) 2445 continue; 2446 if (hyperv_mmio) { 2447 vmbus_reserve_fb(); 2448 break; 2449 } 2450 } 2451 ret_val = 0; 2452 2453 acpi_walk_err: 2454 complete(&probe_event); 2455 if (ret_val) 2456 vmbus_acpi_remove(device); 2457 return ret_val; 2458 } 2459 2460 #ifdef CONFIG_PM_SLEEP 2461 static int vmbus_bus_suspend(struct device *dev) 2462 { 2463 struct vmbus_channel *channel, *sc; 2464 2465 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) { 2466 /* 2467 * We wait here until the completion of any channel 2468 * offers that are currently in progress. 2469 */ 2470 usleep_range(1000, 2000); 2471 } 2472 2473 mutex_lock(&vmbus_connection.channel_mutex); 2474 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2475 if (!is_hvsock_channel(channel)) 2476 continue; 2477 2478 vmbus_force_channel_rescinded(channel); 2479 } 2480 mutex_unlock(&vmbus_connection.channel_mutex); 2481 2482 /* 2483 * Wait until all the sub-channels and hv_sock channels have been 2484 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise 2485 * they would conflict with the new sub-channels that will be created 2486 * in the resume path. hv_sock channels should also be destroyed, but 2487 * a hv_sock channel of an established hv_sock connection can not be 2488 * really destroyed since it may still be referenced by the userspace 2489 * application, so we just force the hv_sock channel to be rescinded 2490 * by vmbus_force_channel_rescinded(), and the userspace application 2491 * will thoroughly destroy the channel after hibernation. 2492 * 2493 * Note: the counter nr_chan_close_on_suspend may never go above 0 if 2494 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM. 2495 */ 2496 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0) 2497 wait_for_completion(&vmbus_connection.ready_for_suspend_event); 2498 2499 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) { 2500 pr_err("Can not suspend due to a previous failed resuming\n"); 2501 return -EBUSY; 2502 } 2503 2504 mutex_lock(&vmbus_connection.channel_mutex); 2505 2506 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2507 /* 2508 * Remove the channel from the array of channels and invalidate 2509 * the channel's relid. Upon resume, vmbus_onoffer() will fix 2510 * up the relid (and other fields, if necessary) and add the 2511 * channel back to the array. 2512 */ 2513 vmbus_channel_unmap_relid(channel); 2514 channel->offermsg.child_relid = INVALID_RELID; 2515 2516 if (is_hvsock_channel(channel)) { 2517 if (!channel->rescind) { 2518 pr_err("hv_sock channel not rescinded!\n"); 2519 WARN_ON_ONCE(1); 2520 } 2521 continue; 2522 } 2523 2524 list_for_each_entry(sc, &channel->sc_list, sc_list) { 2525 pr_err("Sub-channel not deleted!\n"); 2526 WARN_ON_ONCE(1); 2527 } 2528 2529 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume); 2530 } 2531 2532 mutex_unlock(&vmbus_connection.channel_mutex); 2533 2534 vmbus_initiate_unload(false); 2535 2536 /* Reset the event for the next resume. */ 2537 reinit_completion(&vmbus_connection.ready_for_resume_event); 2538 2539 return 0; 2540 } 2541 2542 static int vmbus_bus_resume(struct device *dev) 2543 { 2544 struct vmbus_channel_msginfo *msginfo; 2545 size_t msgsize; 2546 int ret; 2547 2548 /* 2549 * We only use the 'vmbus_proto_version', which was in use before 2550 * hibernation, to re-negotiate with the host. 2551 */ 2552 if (!vmbus_proto_version) { 2553 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version); 2554 return -EINVAL; 2555 } 2556 2557 msgsize = sizeof(*msginfo) + 2558 sizeof(struct vmbus_channel_initiate_contact); 2559 2560 msginfo = kzalloc(msgsize, GFP_KERNEL); 2561 2562 if (msginfo == NULL) 2563 return -ENOMEM; 2564 2565 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version); 2566 2567 kfree(msginfo); 2568 2569 if (ret != 0) 2570 return ret; 2571 2572 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0); 2573 2574 vmbus_request_offers(); 2575 2576 if (wait_for_completion_timeout( 2577 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0) 2578 pr_err("Some vmbus device is missing after suspending?\n"); 2579 2580 /* Reset the event for the next suspend. */ 2581 reinit_completion(&vmbus_connection.ready_for_suspend_event); 2582 2583 return 0; 2584 } 2585 #else 2586 #define vmbus_bus_suspend NULL 2587 #define vmbus_bus_resume NULL 2588 #endif /* CONFIG_PM_SLEEP */ 2589 2590 static const struct acpi_device_id vmbus_acpi_device_ids[] = { 2591 {"VMBUS", 0}, 2592 {"VMBus", 0}, 2593 {"", 0}, 2594 }; 2595 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids); 2596 2597 /* 2598 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with 2599 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in 2600 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see 2601 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() -> 2602 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's 2603 * resume callback must also run via the "noirq" ops. 2604 * 2605 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment 2606 * earlier in this file before vmbus_pm. 2607 */ 2608 2609 static const struct dev_pm_ops vmbus_bus_pm = { 2610 .suspend_noirq = NULL, 2611 .resume_noirq = NULL, 2612 .freeze_noirq = vmbus_bus_suspend, 2613 .thaw_noirq = vmbus_bus_resume, 2614 .poweroff_noirq = vmbus_bus_suspend, 2615 .restore_noirq = vmbus_bus_resume 2616 }; 2617 2618 static struct acpi_driver vmbus_acpi_driver = { 2619 .name = "vmbus", 2620 .ids = vmbus_acpi_device_ids, 2621 .ops = { 2622 .add = vmbus_acpi_add, 2623 .remove = vmbus_acpi_remove, 2624 }, 2625 .drv.pm = &vmbus_bus_pm, 2626 }; 2627 2628 static void hv_kexec_handler(void) 2629 { 2630 hv_stimer_global_cleanup(); 2631 vmbus_initiate_unload(false); 2632 /* Make sure conn_state is set as hv_synic_cleanup checks for it */ 2633 mb(); 2634 cpuhp_remove_state(hyperv_cpuhp_online); 2635 }; 2636 2637 static void hv_crash_handler(struct pt_regs *regs) 2638 { 2639 int cpu; 2640 2641 vmbus_initiate_unload(true); 2642 /* 2643 * In crash handler we can't schedule synic cleanup for all CPUs, 2644 * doing the cleanup for current CPU only. This should be sufficient 2645 * for kdump. 2646 */ 2647 cpu = smp_processor_id(); 2648 hv_stimer_cleanup(cpu); 2649 hv_synic_disable_regs(cpu); 2650 }; 2651 2652 static int hv_synic_suspend(void) 2653 { 2654 /* 2655 * When we reach here, all the non-boot CPUs have been offlined. 2656 * If we're in a legacy configuration where stimer Direct Mode is 2657 * not enabled, the stimers on the non-boot CPUs have been unbound 2658 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() -> 2659 * hv_stimer_cleanup() -> clockevents_unbind_device(). 2660 * 2661 * hv_synic_suspend() only runs on CPU0 with interrupts disabled. 2662 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because: 2663 * 1) it's unnecessary as interrupts remain disabled between 2664 * syscore_suspend() and syscore_resume(): see create_image() and 2665 * resume_target_kernel() 2666 * 2) the stimer on CPU0 is automatically disabled later by 2667 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ... 2668 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown() 2669 * 3) a warning would be triggered if we call 2670 * clockevents_unbind_device(), which may sleep, in an 2671 * interrupts-disabled context. 2672 */ 2673 2674 hv_synic_disable_regs(0); 2675 2676 return 0; 2677 } 2678 2679 static void hv_synic_resume(void) 2680 { 2681 hv_synic_enable_regs(0); 2682 2683 /* 2684 * Note: we don't need to call hv_stimer_init(0), because the timer 2685 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is 2686 * automatically re-enabled in timekeeping_resume(). 2687 */ 2688 } 2689 2690 /* The callbacks run only on CPU0, with irqs_disabled. */ 2691 static struct syscore_ops hv_synic_syscore_ops = { 2692 .suspend = hv_synic_suspend, 2693 .resume = hv_synic_resume, 2694 }; 2695 2696 static int __init hv_acpi_init(void) 2697 { 2698 int ret, t; 2699 2700 if (!hv_is_hyperv_initialized()) 2701 return -ENODEV; 2702 2703 if (hv_root_partition) 2704 return 0; 2705 2706 init_completion(&probe_event); 2707 2708 /* 2709 * Get ACPI resources first. 2710 */ 2711 ret = acpi_bus_register_driver(&vmbus_acpi_driver); 2712 2713 if (ret) 2714 return ret; 2715 2716 t = wait_for_completion_timeout(&probe_event, 5*HZ); 2717 if (t == 0) { 2718 ret = -ETIMEDOUT; 2719 goto cleanup; 2720 } 2721 2722 /* 2723 * If we're on an architecture with a hardcoded hypervisor 2724 * vector (i.e. x86/x64), override the VMbus interrupt found 2725 * in the ACPI tables. Ensure vmbus_irq is not set since the 2726 * normal Linux IRQ mechanism is not used in this case. 2727 */ 2728 #ifdef HYPERVISOR_CALLBACK_VECTOR 2729 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR; 2730 vmbus_irq = -1; 2731 #endif 2732 2733 hv_debug_init(); 2734 2735 ret = vmbus_bus_init(); 2736 if (ret) 2737 goto cleanup; 2738 2739 hv_setup_kexec_handler(hv_kexec_handler); 2740 hv_setup_crash_handler(hv_crash_handler); 2741 2742 register_syscore_ops(&hv_synic_syscore_ops); 2743 2744 return 0; 2745 2746 cleanup: 2747 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2748 hv_acpi_dev = NULL; 2749 return ret; 2750 } 2751 2752 static void __exit vmbus_exit(void) 2753 { 2754 int cpu; 2755 2756 unregister_syscore_ops(&hv_synic_syscore_ops); 2757 2758 hv_remove_kexec_handler(); 2759 hv_remove_crash_handler(); 2760 vmbus_connection.conn_state = DISCONNECTED; 2761 hv_stimer_global_cleanup(); 2762 vmbus_disconnect(); 2763 if (vmbus_irq == -1) { 2764 hv_remove_vmbus_handler(); 2765 } else { 2766 free_percpu_irq(vmbus_irq, vmbus_evt); 2767 free_percpu(vmbus_evt); 2768 } 2769 for_each_online_cpu(cpu) { 2770 struct hv_per_cpu_context *hv_cpu 2771 = per_cpu_ptr(hv_context.cpu_context, cpu); 2772 2773 tasklet_kill(&hv_cpu->msg_dpc); 2774 } 2775 hv_debug_rm_all_dir(); 2776 2777 vmbus_free_channels(); 2778 kfree(vmbus_connection.channels); 2779 2780 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { 2781 kmsg_dump_unregister(&hv_kmsg_dumper); 2782 unregister_die_notifier(&hyperv_die_block); 2783 atomic_notifier_chain_unregister(&panic_notifier_list, 2784 &hyperv_panic_block); 2785 } 2786 2787 free_page((unsigned long)hv_panic_page); 2788 unregister_sysctl_table(hv_ctl_table_hdr); 2789 hv_ctl_table_hdr = NULL; 2790 bus_unregister(&hv_bus); 2791 2792 cpuhp_remove_state(hyperv_cpuhp_online); 2793 hv_synic_free(); 2794 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2795 } 2796 2797 2798 MODULE_LICENSE("GPL"); 2799 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver"); 2800 2801 subsys_initcall(hv_acpi_init); 2802 module_exit(vmbus_exit); 2803