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