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/isolation.h> 25 #include <linux/sched/task_stack.h> 26 27 #include <linux/delay.h> 28 #include <linux/notifier.h> 29 #include <linux/panic_notifier.h> 30 #include <linux/ptrace.h> 31 #include <linux/screen_info.h> 32 #include <linux/kdebug.h> 33 #include <linux/efi.h> 34 #include <linux/random.h> 35 #include <linux/kernel.h> 36 #include <linux/syscore_ops.h> 37 #include <linux/dma-map-ops.h> 38 #include <clocksource/hyperv_timer.h> 39 #include "hyperv_vmbus.h" 40 41 struct vmbus_dynid { 42 struct list_head node; 43 struct hv_vmbus_device_id id; 44 }; 45 46 static struct acpi_device *hv_acpi_dev; 47 48 static struct completion probe_event; 49 50 static int hyperv_cpuhp_online; 51 52 static void *hv_panic_page; 53 54 static long __percpu *vmbus_evt; 55 56 /* Values parsed from ACPI DSDT */ 57 int vmbus_irq; 58 int vmbus_interrupt; 59 60 /* 61 * Boolean to control whether to report panic messages over Hyper-V. 62 * 63 * It can be set via /proc/sys/kernel/hyperv_record_panic_msg 64 */ 65 static int sysctl_record_panic_msg = 1; 66 67 static int hyperv_report_reg(void) 68 { 69 return !sysctl_record_panic_msg || !hv_panic_page; 70 } 71 72 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val, 73 void *args) 74 { 75 struct pt_regs *regs; 76 77 vmbus_initiate_unload(true); 78 79 /* 80 * Hyper-V should be notified only once about a panic. If we will be 81 * doing hv_kmsg_dump() with kmsg data later, don't do the notification 82 * here. 83 */ 84 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE 85 && hyperv_report_reg()) { 86 regs = current_pt_regs(); 87 hyperv_report_panic(regs, val, false); 88 } 89 return NOTIFY_DONE; 90 } 91 92 static int hyperv_die_event(struct notifier_block *nb, unsigned long val, 93 void *args) 94 { 95 struct die_args *die = args; 96 struct pt_regs *regs = die->regs; 97 98 /* Don't notify Hyper-V if the die event is other than oops */ 99 if (val != DIE_OOPS) 100 return NOTIFY_DONE; 101 102 /* 103 * Hyper-V should be notified only once about a panic. If we will be 104 * doing hv_kmsg_dump() with kmsg data later, don't do the notification 105 * here. 106 */ 107 if (hyperv_report_reg()) 108 hyperv_report_panic(regs, val, true); 109 return NOTIFY_DONE; 110 } 111 112 static struct notifier_block hyperv_die_block = { 113 .notifier_call = hyperv_die_event, 114 }; 115 static struct notifier_block hyperv_panic_block = { 116 .notifier_call = hyperv_panic_event, 117 }; 118 119 static const char *fb_mmio_name = "fb_range"; 120 static struct resource *fb_mmio; 121 static struct resource *hyperv_mmio; 122 static DEFINE_MUTEX(hyperv_mmio_lock); 123 124 static int vmbus_exists(void) 125 { 126 if (hv_acpi_dev == NULL) 127 return -ENODEV; 128 129 return 0; 130 } 131 132 static u8 channel_monitor_group(const struct vmbus_channel *channel) 133 { 134 return (u8)channel->offermsg.monitorid / 32; 135 } 136 137 static u8 channel_monitor_offset(const struct vmbus_channel *channel) 138 { 139 return (u8)channel->offermsg.monitorid % 32; 140 } 141 142 static u32 channel_pending(const struct vmbus_channel *channel, 143 const struct hv_monitor_page *monitor_page) 144 { 145 u8 monitor_group = channel_monitor_group(channel); 146 147 return monitor_page->trigger_group[monitor_group].pending; 148 } 149 150 static u32 channel_latency(const struct vmbus_channel *channel, 151 const struct hv_monitor_page *monitor_page) 152 { 153 u8 monitor_group = channel_monitor_group(channel); 154 u8 monitor_offset = channel_monitor_offset(channel); 155 156 return monitor_page->latency[monitor_group][monitor_offset]; 157 } 158 159 static u32 channel_conn_id(struct vmbus_channel *channel, 160 struct hv_monitor_page *monitor_page) 161 { 162 u8 monitor_group = channel_monitor_group(channel); 163 u8 monitor_offset = channel_monitor_offset(channel); 164 165 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id; 166 } 167 168 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr, 169 char *buf) 170 { 171 struct hv_device *hv_dev = device_to_hv_device(dev); 172 173 if (!hv_dev->channel) 174 return -ENODEV; 175 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid); 176 } 177 static DEVICE_ATTR_RO(id); 178 179 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr, 180 char *buf) 181 { 182 struct hv_device *hv_dev = device_to_hv_device(dev); 183 184 if (!hv_dev->channel) 185 return -ENODEV; 186 return sprintf(buf, "%d\n", hv_dev->channel->state); 187 } 188 static DEVICE_ATTR_RO(state); 189 190 static ssize_t monitor_id_show(struct device *dev, 191 struct device_attribute *dev_attr, char *buf) 192 { 193 struct hv_device *hv_dev = device_to_hv_device(dev); 194 195 if (!hv_dev->channel) 196 return -ENODEV; 197 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid); 198 } 199 static DEVICE_ATTR_RO(monitor_id); 200 201 static ssize_t class_id_show(struct device *dev, 202 struct device_attribute *dev_attr, char *buf) 203 { 204 struct hv_device *hv_dev = device_to_hv_device(dev); 205 206 if (!hv_dev->channel) 207 return -ENODEV; 208 return sprintf(buf, "{%pUl}\n", 209 &hv_dev->channel->offermsg.offer.if_type); 210 } 211 static DEVICE_ATTR_RO(class_id); 212 213 static ssize_t device_id_show(struct device *dev, 214 struct device_attribute *dev_attr, char *buf) 215 { 216 struct hv_device *hv_dev = device_to_hv_device(dev); 217 218 if (!hv_dev->channel) 219 return -ENODEV; 220 return sprintf(buf, "{%pUl}\n", 221 &hv_dev->channel->offermsg.offer.if_instance); 222 } 223 static DEVICE_ATTR_RO(device_id); 224 225 static ssize_t modalias_show(struct device *dev, 226 struct device_attribute *dev_attr, char *buf) 227 { 228 struct hv_device *hv_dev = device_to_hv_device(dev); 229 230 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type); 231 } 232 static DEVICE_ATTR_RO(modalias); 233 234 #ifdef CONFIG_NUMA 235 static ssize_t numa_node_show(struct device *dev, 236 struct device_attribute *attr, char *buf) 237 { 238 struct hv_device *hv_dev = device_to_hv_device(dev); 239 240 if (!hv_dev->channel) 241 return -ENODEV; 242 243 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu)); 244 } 245 static DEVICE_ATTR_RO(numa_node); 246 #endif 247 248 static ssize_t server_monitor_pending_show(struct device *dev, 249 struct device_attribute *dev_attr, 250 char *buf) 251 { 252 struct hv_device *hv_dev = device_to_hv_device(dev); 253 254 if (!hv_dev->channel) 255 return -ENODEV; 256 return sprintf(buf, "%d\n", 257 channel_pending(hv_dev->channel, 258 vmbus_connection.monitor_pages[0])); 259 } 260 static DEVICE_ATTR_RO(server_monitor_pending); 261 262 static ssize_t client_monitor_pending_show(struct device *dev, 263 struct device_attribute *dev_attr, 264 char *buf) 265 { 266 struct hv_device *hv_dev = device_to_hv_device(dev); 267 268 if (!hv_dev->channel) 269 return -ENODEV; 270 return sprintf(buf, "%d\n", 271 channel_pending(hv_dev->channel, 272 vmbus_connection.monitor_pages[1])); 273 } 274 static DEVICE_ATTR_RO(client_monitor_pending); 275 276 static ssize_t server_monitor_latency_show(struct device *dev, 277 struct device_attribute *dev_attr, 278 char *buf) 279 { 280 struct hv_device *hv_dev = device_to_hv_device(dev); 281 282 if (!hv_dev->channel) 283 return -ENODEV; 284 return sprintf(buf, "%d\n", 285 channel_latency(hv_dev->channel, 286 vmbus_connection.monitor_pages[0])); 287 } 288 static DEVICE_ATTR_RO(server_monitor_latency); 289 290 static ssize_t client_monitor_latency_show(struct device *dev, 291 struct device_attribute *dev_attr, 292 char *buf) 293 { 294 struct hv_device *hv_dev = device_to_hv_device(dev); 295 296 if (!hv_dev->channel) 297 return -ENODEV; 298 return sprintf(buf, "%d\n", 299 channel_latency(hv_dev->channel, 300 vmbus_connection.monitor_pages[1])); 301 } 302 static DEVICE_ATTR_RO(client_monitor_latency); 303 304 static ssize_t server_monitor_conn_id_show(struct device *dev, 305 struct device_attribute *dev_attr, 306 char *buf) 307 { 308 struct hv_device *hv_dev = device_to_hv_device(dev); 309 310 if (!hv_dev->channel) 311 return -ENODEV; 312 return sprintf(buf, "%d\n", 313 channel_conn_id(hv_dev->channel, 314 vmbus_connection.monitor_pages[0])); 315 } 316 static DEVICE_ATTR_RO(server_monitor_conn_id); 317 318 static ssize_t client_monitor_conn_id_show(struct device *dev, 319 struct device_attribute *dev_attr, 320 char *buf) 321 { 322 struct hv_device *hv_dev = device_to_hv_device(dev); 323 324 if (!hv_dev->channel) 325 return -ENODEV; 326 return sprintf(buf, "%d\n", 327 channel_conn_id(hv_dev->channel, 328 vmbus_connection.monitor_pages[1])); 329 } 330 static DEVICE_ATTR_RO(client_monitor_conn_id); 331 332 static ssize_t out_intr_mask_show(struct device *dev, 333 struct device_attribute *dev_attr, char *buf) 334 { 335 struct hv_device *hv_dev = device_to_hv_device(dev); 336 struct hv_ring_buffer_debug_info outbound; 337 int ret; 338 339 if (!hv_dev->channel) 340 return -ENODEV; 341 342 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 343 &outbound); 344 if (ret < 0) 345 return ret; 346 347 return sprintf(buf, "%d\n", outbound.current_interrupt_mask); 348 } 349 static DEVICE_ATTR_RO(out_intr_mask); 350 351 static ssize_t out_read_index_show(struct device *dev, 352 struct device_attribute *dev_attr, char *buf) 353 { 354 struct hv_device *hv_dev = device_to_hv_device(dev); 355 struct hv_ring_buffer_debug_info outbound; 356 int ret; 357 358 if (!hv_dev->channel) 359 return -ENODEV; 360 361 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 362 &outbound); 363 if (ret < 0) 364 return ret; 365 return sprintf(buf, "%d\n", outbound.current_read_index); 366 } 367 static DEVICE_ATTR_RO(out_read_index); 368 369 static ssize_t out_write_index_show(struct device *dev, 370 struct device_attribute *dev_attr, 371 char *buf) 372 { 373 struct hv_device *hv_dev = device_to_hv_device(dev); 374 struct hv_ring_buffer_debug_info outbound; 375 int ret; 376 377 if (!hv_dev->channel) 378 return -ENODEV; 379 380 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 381 &outbound); 382 if (ret < 0) 383 return ret; 384 return sprintf(buf, "%d\n", outbound.current_write_index); 385 } 386 static DEVICE_ATTR_RO(out_write_index); 387 388 static ssize_t out_read_bytes_avail_show(struct device *dev, 389 struct device_attribute *dev_attr, 390 char *buf) 391 { 392 struct hv_device *hv_dev = device_to_hv_device(dev); 393 struct hv_ring_buffer_debug_info outbound; 394 int ret; 395 396 if (!hv_dev->channel) 397 return -ENODEV; 398 399 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 400 &outbound); 401 if (ret < 0) 402 return ret; 403 return sprintf(buf, "%d\n", outbound.bytes_avail_toread); 404 } 405 static DEVICE_ATTR_RO(out_read_bytes_avail); 406 407 static ssize_t out_write_bytes_avail_show(struct device *dev, 408 struct device_attribute *dev_attr, 409 char *buf) 410 { 411 struct hv_device *hv_dev = device_to_hv_device(dev); 412 struct hv_ring_buffer_debug_info outbound; 413 int ret; 414 415 if (!hv_dev->channel) 416 return -ENODEV; 417 418 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, 419 &outbound); 420 if (ret < 0) 421 return ret; 422 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite); 423 } 424 static DEVICE_ATTR_RO(out_write_bytes_avail); 425 426 static ssize_t in_intr_mask_show(struct device *dev, 427 struct device_attribute *dev_attr, char *buf) 428 { 429 struct hv_device *hv_dev = device_to_hv_device(dev); 430 struct hv_ring_buffer_debug_info inbound; 431 int ret; 432 433 if (!hv_dev->channel) 434 return -ENODEV; 435 436 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 437 if (ret < 0) 438 return ret; 439 440 return sprintf(buf, "%d\n", inbound.current_interrupt_mask); 441 } 442 static DEVICE_ATTR_RO(in_intr_mask); 443 444 static ssize_t in_read_index_show(struct device *dev, 445 struct device_attribute *dev_attr, char *buf) 446 { 447 struct hv_device *hv_dev = device_to_hv_device(dev); 448 struct hv_ring_buffer_debug_info inbound; 449 int ret; 450 451 if (!hv_dev->channel) 452 return -ENODEV; 453 454 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 455 if (ret < 0) 456 return ret; 457 458 return sprintf(buf, "%d\n", inbound.current_read_index); 459 } 460 static DEVICE_ATTR_RO(in_read_index); 461 462 static ssize_t in_write_index_show(struct device *dev, 463 struct device_attribute *dev_attr, char *buf) 464 { 465 struct hv_device *hv_dev = device_to_hv_device(dev); 466 struct hv_ring_buffer_debug_info inbound; 467 int ret; 468 469 if (!hv_dev->channel) 470 return -ENODEV; 471 472 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 473 if (ret < 0) 474 return ret; 475 476 return sprintf(buf, "%d\n", inbound.current_write_index); 477 } 478 static DEVICE_ATTR_RO(in_write_index); 479 480 static ssize_t in_read_bytes_avail_show(struct device *dev, 481 struct device_attribute *dev_attr, 482 char *buf) 483 { 484 struct hv_device *hv_dev = device_to_hv_device(dev); 485 struct hv_ring_buffer_debug_info inbound; 486 int ret; 487 488 if (!hv_dev->channel) 489 return -ENODEV; 490 491 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 492 if (ret < 0) 493 return ret; 494 495 return sprintf(buf, "%d\n", inbound.bytes_avail_toread); 496 } 497 static DEVICE_ATTR_RO(in_read_bytes_avail); 498 499 static ssize_t in_write_bytes_avail_show(struct device *dev, 500 struct device_attribute *dev_attr, 501 char *buf) 502 { 503 struct hv_device *hv_dev = device_to_hv_device(dev); 504 struct hv_ring_buffer_debug_info inbound; 505 int ret; 506 507 if (!hv_dev->channel) 508 return -ENODEV; 509 510 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); 511 if (ret < 0) 512 return ret; 513 514 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite); 515 } 516 static DEVICE_ATTR_RO(in_write_bytes_avail); 517 518 static ssize_t channel_vp_mapping_show(struct device *dev, 519 struct device_attribute *dev_attr, 520 char *buf) 521 { 522 struct hv_device *hv_dev = device_to_hv_device(dev); 523 struct vmbus_channel *channel = hv_dev->channel, *cur_sc; 524 int buf_size = PAGE_SIZE, n_written, tot_written; 525 struct list_head *cur; 526 527 if (!channel) 528 return -ENODEV; 529 530 mutex_lock(&vmbus_connection.channel_mutex); 531 532 tot_written = snprintf(buf, buf_size, "%u:%u\n", 533 channel->offermsg.child_relid, channel->target_cpu); 534 535 list_for_each(cur, &channel->sc_list) { 536 if (tot_written >= buf_size - 1) 537 break; 538 539 cur_sc = list_entry(cur, struct vmbus_channel, sc_list); 540 n_written = scnprintf(buf + tot_written, 541 buf_size - tot_written, 542 "%u:%u\n", 543 cur_sc->offermsg.child_relid, 544 cur_sc->target_cpu); 545 tot_written += n_written; 546 } 547 548 mutex_unlock(&vmbus_connection.channel_mutex); 549 550 return tot_written; 551 } 552 static DEVICE_ATTR_RO(channel_vp_mapping); 553 554 static ssize_t vendor_show(struct device *dev, 555 struct device_attribute *dev_attr, 556 char *buf) 557 { 558 struct hv_device *hv_dev = device_to_hv_device(dev); 559 560 return sprintf(buf, "0x%x\n", hv_dev->vendor_id); 561 } 562 static DEVICE_ATTR_RO(vendor); 563 564 static ssize_t device_show(struct device *dev, 565 struct device_attribute *dev_attr, 566 char *buf) 567 { 568 struct hv_device *hv_dev = device_to_hv_device(dev); 569 570 return sprintf(buf, "0x%x\n", hv_dev->device_id); 571 } 572 static DEVICE_ATTR_RO(device); 573 574 static ssize_t driver_override_store(struct device *dev, 575 struct device_attribute *attr, 576 const char *buf, size_t count) 577 { 578 struct hv_device *hv_dev = device_to_hv_device(dev); 579 int ret; 580 581 ret = driver_set_override(dev, &hv_dev->driver_override, buf, count); 582 if (ret) 583 return ret; 584 585 return count; 586 } 587 588 static ssize_t driver_override_show(struct device *dev, 589 struct device_attribute *attr, char *buf) 590 { 591 struct hv_device *hv_dev = device_to_hv_device(dev); 592 ssize_t len; 593 594 device_lock(dev); 595 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override); 596 device_unlock(dev); 597 598 return len; 599 } 600 static DEVICE_ATTR_RW(driver_override); 601 602 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */ 603 static struct attribute *vmbus_dev_attrs[] = { 604 &dev_attr_id.attr, 605 &dev_attr_state.attr, 606 &dev_attr_monitor_id.attr, 607 &dev_attr_class_id.attr, 608 &dev_attr_device_id.attr, 609 &dev_attr_modalias.attr, 610 #ifdef CONFIG_NUMA 611 &dev_attr_numa_node.attr, 612 #endif 613 &dev_attr_server_monitor_pending.attr, 614 &dev_attr_client_monitor_pending.attr, 615 &dev_attr_server_monitor_latency.attr, 616 &dev_attr_client_monitor_latency.attr, 617 &dev_attr_server_monitor_conn_id.attr, 618 &dev_attr_client_monitor_conn_id.attr, 619 &dev_attr_out_intr_mask.attr, 620 &dev_attr_out_read_index.attr, 621 &dev_attr_out_write_index.attr, 622 &dev_attr_out_read_bytes_avail.attr, 623 &dev_attr_out_write_bytes_avail.attr, 624 &dev_attr_in_intr_mask.attr, 625 &dev_attr_in_read_index.attr, 626 &dev_attr_in_write_index.attr, 627 &dev_attr_in_read_bytes_avail.attr, 628 &dev_attr_in_write_bytes_avail.attr, 629 &dev_attr_channel_vp_mapping.attr, 630 &dev_attr_vendor.attr, 631 &dev_attr_device.attr, 632 &dev_attr_driver_override.attr, 633 NULL, 634 }; 635 636 /* 637 * Device-level attribute_group callback function. Returns the permission for 638 * each attribute, and returns 0 if an attribute is not visible. 639 */ 640 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj, 641 struct attribute *attr, int idx) 642 { 643 struct device *dev = kobj_to_dev(kobj); 644 const struct hv_device *hv_dev = device_to_hv_device(dev); 645 646 /* Hide the monitor attributes if the monitor mechanism is not used. */ 647 if (!hv_dev->channel->offermsg.monitor_allocated && 648 (attr == &dev_attr_monitor_id.attr || 649 attr == &dev_attr_server_monitor_pending.attr || 650 attr == &dev_attr_client_monitor_pending.attr || 651 attr == &dev_attr_server_monitor_latency.attr || 652 attr == &dev_attr_client_monitor_latency.attr || 653 attr == &dev_attr_server_monitor_conn_id.attr || 654 attr == &dev_attr_client_monitor_conn_id.attr)) 655 return 0; 656 657 return attr->mode; 658 } 659 660 static const struct attribute_group vmbus_dev_group = { 661 .attrs = vmbus_dev_attrs, 662 .is_visible = vmbus_dev_attr_is_visible 663 }; 664 __ATTRIBUTE_GROUPS(vmbus_dev); 665 666 /* Set up the attribute for /sys/bus/vmbus/hibernation */ 667 static ssize_t hibernation_show(struct bus_type *bus, char *buf) 668 { 669 return sprintf(buf, "%d\n", !!hv_is_hibernation_supported()); 670 } 671 672 static BUS_ATTR_RO(hibernation); 673 674 static struct attribute *vmbus_bus_attrs[] = { 675 &bus_attr_hibernation.attr, 676 NULL, 677 }; 678 static const struct attribute_group vmbus_bus_group = { 679 .attrs = vmbus_bus_attrs, 680 }; 681 __ATTRIBUTE_GROUPS(vmbus_bus); 682 683 /* 684 * vmbus_uevent - add uevent for our device 685 * 686 * This routine is invoked when a device is added or removed on the vmbus to 687 * generate a uevent to udev in the userspace. The udev will then look at its 688 * rule and the uevent generated here to load the appropriate driver 689 * 690 * The alias string will be of the form vmbus:guid where guid is the string 691 * representation of the device guid (each byte of the guid will be 692 * represented with two hex characters. 693 */ 694 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env) 695 { 696 struct hv_device *dev = device_to_hv_device(device); 697 const char *format = "MODALIAS=vmbus:%*phN"; 698 699 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type); 700 } 701 702 static const struct hv_vmbus_device_id * 703 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid) 704 { 705 if (id == NULL) 706 return NULL; /* empty device table */ 707 708 for (; !guid_is_null(&id->guid); id++) 709 if (guid_equal(&id->guid, guid)) 710 return id; 711 712 return NULL; 713 } 714 715 static const struct hv_vmbus_device_id * 716 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid) 717 { 718 const struct hv_vmbus_device_id *id = NULL; 719 struct vmbus_dynid *dynid; 720 721 spin_lock(&drv->dynids.lock); 722 list_for_each_entry(dynid, &drv->dynids.list, node) { 723 if (guid_equal(&dynid->id.guid, guid)) { 724 id = &dynid->id; 725 break; 726 } 727 } 728 spin_unlock(&drv->dynids.lock); 729 730 return id; 731 } 732 733 static const struct hv_vmbus_device_id vmbus_device_null; 734 735 /* 736 * Return a matching hv_vmbus_device_id pointer. 737 * If there is no match, return NULL. 738 */ 739 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv, 740 struct hv_device *dev) 741 { 742 const guid_t *guid = &dev->dev_type; 743 const struct hv_vmbus_device_id *id; 744 745 /* When driver_override is set, only bind to the matching driver */ 746 if (dev->driver_override && strcmp(dev->driver_override, drv->name)) 747 return NULL; 748 749 /* Look at the dynamic ids first, before the static ones */ 750 id = hv_vmbus_dynid_match(drv, guid); 751 if (!id) 752 id = hv_vmbus_dev_match(drv->id_table, guid); 753 754 /* driver_override will always match, send a dummy id */ 755 if (!id && dev->driver_override) 756 id = &vmbus_device_null; 757 758 return id; 759 } 760 761 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */ 762 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid) 763 { 764 struct vmbus_dynid *dynid; 765 766 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL); 767 if (!dynid) 768 return -ENOMEM; 769 770 dynid->id.guid = *guid; 771 772 spin_lock(&drv->dynids.lock); 773 list_add_tail(&dynid->node, &drv->dynids.list); 774 spin_unlock(&drv->dynids.lock); 775 776 return driver_attach(&drv->driver); 777 } 778 779 static void vmbus_free_dynids(struct hv_driver *drv) 780 { 781 struct vmbus_dynid *dynid, *n; 782 783 spin_lock(&drv->dynids.lock); 784 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 785 list_del(&dynid->node); 786 kfree(dynid); 787 } 788 spin_unlock(&drv->dynids.lock); 789 } 790 791 /* 792 * store_new_id - sysfs frontend to vmbus_add_dynid() 793 * 794 * Allow GUIDs to be added to an existing driver via sysfs. 795 */ 796 static ssize_t new_id_store(struct device_driver *driver, const char *buf, 797 size_t count) 798 { 799 struct hv_driver *drv = drv_to_hv_drv(driver); 800 guid_t guid; 801 ssize_t retval; 802 803 retval = guid_parse(buf, &guid); 804 if (retval) 805 return retval; 806 807 if (hv_vmbus_dynid_match(drv, &guid)) 808 return -EEXIST; 809 810 retval = vmbus_add_dynid(drv, &guid); 811 if (retval) 812 return retval; 813 return count; 814 } 815 static DRIVER_ATTR_WO(new_id); 816 817 /* 818 * store_remove_id - remove a PCI device ID from this driver 819 * 820 * Removes a dynamic pci device ID to this driver. 821 */ 822 static ssize_t remove_id_store(struct device_driver *driver, const char *buf, 823 size_t count) 824 { 825 struct hv_driver *drv = drv_to_hv_drv(driver); 826 struct vmbus_dynid *dynid, *n; 827 guid_t guid; 828 ssize_t retval; 829 830 retval = guid_parse(buf, &guid); 831 if (retval) 832 return retval; 833 834 retval = -ENODEV; 835 spin_lock(&drv->dynids.lock); 836 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 837 struct hv_vmbus_device_id *id = &dynid->id; 838 839 if (guid_equal(&id->guid, &guid)) { 840 list_del(&dynid->node); 841 kfree(dynid); 842 retval = count; 843 break; 844 } 845 } 846 spin_unlock(&drv->dynids.lock); 847 848 return retval; 849 } 850 static DRIVER_ATTR_WO(remove_id); 851 852 static struct attribute *vmbus_drv_attrs[] = { 853 &driver_attr_new_id.attr, 854 &driver_attr_remove_id.attr, 855 NULL, 856 }; 857 ATTRIBUTE_GROUPS(vmbus_drv); 858 859 860 /* 861 * vmbus_match - Attempt to match the specified device to the specified driver 862 */ 863 static int vmbus_match(struct device *device, struct device_driver *driver) 864 { 865 struct hv_driver *drv = drv_to_hv_drv(driver); 866 struct hv_device *hv_dev = device_to_hv_device(device); 867 868 /* The hv_sock driver handles all hv_sock offers. */ 869 if (is_hvsock_channel(hv_dev->channel)) 870 return drv->hvsock; 871 872 if (hv_vmbus_get_id(drv, hv_dev)) 873 return 1; 874 875 return 0; 876 } 877 878 /* 879 * vmbus_probe - Add the new vmbus's child device 880 */ 881 static int vmbus_probe(struct device *child_device) 882 { 883 int ret = 0; 884 struct hv_driver *drv = 885 drv_to_hv_drv(child_device->driver); 886 struct hv_device *dev = device_to_hv_device(child_device); 887 const struct hv_vmbus_device_id *dev_id; 888 889 dev_id = hv_vmbus_get_id(drv, dev); 890 if (drv->probe) { 891 ret = drv->probe(dev, dev_id); 892 if (ret != 0) 893 pr_err("probe failed for device %s (%d)\n", 894 dev_name(child_device), ret); 895 896 } else { 897 pr_err("probe not set for driver %s\n", 898 dev_name(child_device)); 899 ret = -ENODEV; 900 } 901 return ret; 902 } 903 904 /* 905 * vmbus_dma_configure -- Configure DMA coherence for VMbus device 906 */ 907 static int vmbus_dma_configure(struct device *child_device) 908 { 909 /* 910 * On ARM64, propagate the DMA coherence setting from the top level 911 * VMbus ACPI device to the child VMbus device being added here. 912 * On x86/x64 coherence is assumed and these calls have no effect. 913 */ 914 hv_setup_dma_ops(child_device, 915 device_get_dma_attr(&hv_acpi_dev->dev) == DEV_DMA_COHERENT); 916 return 0; 917 } 918 919 /* 920 * vmbus_remove - Remove a vmbus device 921 */ 922 static void vmbus_remove(struct device *child_device) 923 { 924 struct hv_driver *drv; 925 struct hv_device *dev = device_to_hv_device(child_device); 926 927 if (child_device->driver) { 928 drv = drv_to_hv_drv(child_device->driver); 929 if (drv->remove) 930 drv->remove(dev); 931 } 932 } 933 934 /* 935 * vmbus_shutdown - Shutdown a vmbus device 936 */ 937 static void vmbus_shutdown(struct device *child_device) 938 { 939 struct hv_driver *drv; 940 struct hv_device *dev = device_to_hv_device(child_device); 941 942 943 /* The device may not be attached yet */ 944 if (!child_device->driver) 945 return; 946 947 drv = drv_to_hv_drv(child_device->driver); 948 949 if (drv->shutdown) 950 drv->shutdown(dev); 951 } 952 953 #ifdef CONFIG_PM_SLEEP 954 /* 955 * vmbus_suspend - Suspend a vmbus device 956 */ 957 static int vmbus_suspend(struct device *child_device) 958 { 959 struct hv_driver *drv; 960 struct hv_device *dev = device_to_hv_device(child_device); 961 962 /* The device may not be attached yet */ 963 if (!child_device->driver) 964 return 0; 965 966 drv = drv_to_hv_drv(child_device->driver); 967 if (!drv->suspend) 968 return -EOPNOTSUPP; 969 970 return drv->suspend(dev); 971 } 972 973 /* 974 * vmbus_resume - Resume a vmbus device 975 */ 976 static int vmbus_resume(struct device *child_device) 977 { 978 struct hv_driver *drv; 979 struct hv_device *dev = device_to_hv_device(child_device); 980 981 /* The device may not be attached yet */ 982 if (!child_device->driver) 983 return 0; 984 985 drv = drv_to_hv_drv(child_device->driver); 986 if (!drv->resume) 987 return -EOPNOTSUPP; 988 989 return drv->resume(dev); 990 } 991 #else 992 #define vmbus_suspend NULL 993 #define vmbus_resume NULL 994 #endif /* CONFIG_PM_SLEEP */ 995 996 /* 997 * vmbus_device_release - Final callback release of the vmbus child device 998 */ 999 static void vmbus_device_release(struct device *device) 1000 { 1001 struct hv_device *hv_dev = device_to_hv_device(device); 1002 struct vmbus_channel *channel = hv_dev->channel; 1003 1004 hv_debug_rm_dev_dir(hv_dev); 1005 1006 mutex_lock(&vmbus_connection.channel_mutex); 1007 hv_process_channel_removal(channel); 1008 mutex_unlock(&vmbus_connection.channel_mutex); 1009 kfree(hv_dev); 1010 } 1011 1012 /* 1013 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm. 1014 * 1015 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we 1016 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there 1017 * is no way to wake up a Generation-2 VM. 1018 * 1019 * The other 4 ops are for hibernation. 1020 */ 1021 1022 static const struct dev_pm_ops vmbus_pm = { 1023 .suspend_noirq = NULL, 1024 .resume_noirq = NULL, 1025 .freeze_noirq = vmbus_suspend, 1026 .thaw_noirq = vmbus_resume, 1027 .poweroff_noirq = vmbus_suspend, 1028 .restore_noirq = vmbus_resume, 1029 }; 1030 1031 /* The one and only one */ 1032 static struct bus_type hv_bus = { 1033 .name = "vmbus", 1034 .match = vmbus_match, 1035 .shutdown = vmbus_shutdown, 1036 .remove = vmbus_remove, 1037 .probe = vmbus_probe, 1038 .uevent = vmbus_uevent, 1039 .dma_configure = vmbus_dma_configure, 1040 .dev_groups = vmbus_dev_groups, 1041 .drv_groups = vmbus_drv_groups, 1042 .bus_groups = vmbus_bus_groups, 1043 .pm = &vmbus_pm, 1044 }; 1045 1046 struct onmessage_work_context { 1047 struct work_struct work; 1048 struct { 1049 struct hv_message_header header; 1050 u8 payload[]; 1051 } msg; 1052 }; 1053 1054 static void vmbus_onmessage_work(struct work_struct *work) 1055 { 1056 struct onmessage_work_context *ctx; 1057 1058 /* Do not process messages if we're in DISCONNECTED state */ 1059 if (vmbus_connection.conn_state == DISCONNECTED) 1060 return; 1061 1062 ctx = container_of(work, struct onmessage_work_context, 1063 work); 1064 vmbus_onmessage((struct vmbus_channel_message_header *) 1065 &ctx->msg.payload); 1066 kfree(ctx); 1067 } 1068 1069 void vmbus_on_msg_dpc(unsigned long data) 1070 { 1071 struct hv_per_cpu_context *hv_cpu = (void *)data; 1072 void *page_addr = hv_cpu->synic_message_page; 1073 struct hv_message msg_copy, *msg = (struct hv_message *)page_addr + 1074 VMBUS_MESSAGE_SINT; 1075 struct vmbus_channel_message_header *hdr; 1076 enum vmbus_channel_message_type msgtype; 1077 const struct vmbus_channel_message_table_entry *entry; 1078 struct onmessage_work_context *ctx; 1079 __u8 payload_size; 1080 u32 message_type; 1081 1082 /* 1083 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as 1084 * it is being used in 'struct vmbus_channel_message_header' definition 1085 * which is supposed to match hypervisor ABI. 1086 */ 1087 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32)); 1088 1089 /* 1090 * Since the message is in memory shared with the host, an erroneous or 1091 * malicious Hyper-V could modify the message while vmbus_on_msg_dpc() 1092 * or individual message handlers are executing; to prevent this, copy 1093 * the message into private memory. 1094 */ 1095 memcpy(&msg_copy, msg, sizeof(struct hv_message)); 1096 1097 message_type = msg_copy.header.message_type; 1098 if (message_type == HVMSG_NONE) 1099 /* no msg */ 1100 return; 1101 1102 hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload; 1103 msgtype = hdr->msgtype; 1104 1105 trace_vmbus_on_msg_dpc(hdr); 1106 1107 if (msgtype >= CHANNELMSG_COUNT) { 1108 WARN_ONCE(1, "unknown msgtype=%d\n", msgtype); 1109 goto msg_handled; 1110 } 1111 1112 payload_size = msg_copy.header.payload_size; 1113 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) { 1114 WARN_ONCE(1, "payload size is too large (%d)\n", payload_size); 1115 goto msg_handled; 1116 } 1117 1118 entry = &channel_message_table[msgtype]; 1119 1120 if (!entry->message_handler) 1121 goto msg_handled; 1122 1123 if (payload_size < entry->min_payload_len) { 1124 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size); 1125 goto msg_handled; 1126 } 1127 1128 if (entry->handler_type == VMHT_BLOCKING) { 1129 ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC); 1130 if (ctx == NULL) 1131 return; 1132 1133 INIT_WORK(&ctx->work, vmbus_onmessage_work); 1134 memcpy(&ctx->msg, &msg_copy, sizeof(msg->header) + payload_size); 1135 1136 /* 1137 * The host can generate a rescind message while we 1138 * may still be handling the original offer. We deal with 1139 * this condition by relying on the synchronization provided 1140 * by offer_in_progress and by channel_mutex. See also the 1141 * inline comments in vmbus_onoffer_rescind(). 1142 */ 1143 switch (msgtype) { 1144 case CHANNELMSG_RESCIND_CHANNELOFFER: 1145 /* 1146 * If we are handling the rescind message; 1147 * schedule the work on the global work queue. 1148 * 1149 * The OFFER message and the RESCIND message should 1150 * not be handled by the same serialized work queue, 1151 * because the OFFER handler may call vmbus_open(), 1152 * which tries to open the channel by sending an 1153 * OPEN_CHANNEL message to the host and waits for 1154 * the host's response; however, if the host has 1155 * rescinded the channel before it receives the 1156 * OPEN_CHANNEL message, the host just silently 1157 * ignores the OPEN_CHANNEL message; as a result, 1158 * the guest's OFFER handler hangs for ever, if we 1159 * handle the RESCIND message in the same serialized 1160 * work queue: the RESCIND handler can not start to 1161 * run before the OFFER handler finishes. 1162 */ 1163 if (vmbus_connection.ignore_any_offer_msg) 1164 break; 1165 queue_work(vmbus_connection.rescind_work_queue, &ctx->work); 1166 break; 1167 1168 case CHANNELMSG_OFFERCHANNEL: 1169 /* 1170 * The host sends the offer message of a given channel 1171 * before sending the rescind message of the same 1172 * channel. These messages are sent to the guest's 1173 * connect CPU; the guest then starts processing them 1174 * in the tasklet handler on this CPU: 1175 * 1176 * VMBUS_CONNECT_CPU 1177 * 1178 * [vmbus_on_msg_dpc()] 1179 * atomic_inc() // CHANNELMSG_OFFERCHANNEL 1180 * queue_work() 1181 * ... 1182 * [vmbus_on_msg_dpc()] 1183 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER 1184 * 1185 * We rely on the memory-ordering properties of the 1186 * queue_work() and schedule_work() primitives, which 1187 * guarantee that the atomic increment will be visible 1188 * to the CPUs which will execute the offer & rescind 1189 * works by the time these works will start execution. 1190 */ 1191 if (vmbus_connection.ignore_any_offer_msg) 1192 break; 1193 atomic_inc(&vmbus_connection.offer_in_progress); 1194 fallthrough; 1195 1196 default: 1197 queue_work(vmbus_connection.work_queue, &ctx->work); 1198 } 1199 } else 1200 entry->message_handler(hdr); 1201 1202 msg_handled: 1203 vmbus_signal_eom(msg, message_type); 1204 } 1205 1206 #ifdef CONFIG_PM_SLEEP 1207 /* 1208 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for 1209 * hibernation, because hv_sock connections can not persist across hibernation. 1210 */ 1211 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel) 1212 { 1213 struct onmessage_work_context *ctx; 1214 struct vmbus_channel_rescind_offer *rescind; 1215 1216 WARN_ON(!is_hvsock_channel(channel)); 1217 1218 /* 1219 * Allocation size is small and the allocation should really not fail, 1220 * otherwise the state of the hv_sock connections ends up in limbo. 1221 */ 1222 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind), 1223 GFP_KERNEL | __GFP_NOFAIL); 1224 1225 /* 1226 * So far, these are not really used by Linux. Just set them to the 1227 * reasonable values conforming to the definitions of the fields. 1228 */ 1229 ctx->msg.header.message_type = 1; 1230 ctx->msg.header.payload_size = sizeof(*rescind); 1231 1232 /* These values are actually used by Linux. */ 1233 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload; 1234 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER; 1235 rescind->child_relid = channel->offermsg.child_relid; 1236 1237 INIT_WORK(&ctx->work, vmbus_onmessage_work); 1238 1239 queue_work(vmbus_connection.work_queue, &ctx->work); 1240 } 1241 #endif /* CONFIG_PM_SLEEP */ 1242 1243 /* 1244 * Schedule all channels with events pending 1245 */ 1246 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) 1247 { 1248 unsigned long *recv_int_page; 1249 u32 maxbits, relid; 1250 1251 /* 1252 * The event page can be directly checked to get the id of 1253 * the channel that has the interrupt pending. 1254 */ 1255 void *page_addr = hv_cpu->synic_event_page; 1256 union hv_synic_event_flags *event 1257 = (union hv_synic_event_flags *)page_addr + 1258 VMBUS_MESSAGE_SINT; 1259 1260 maxbits = HV_EVENT_FLAGS_COUNT; 1261 recv_int_page = event->flags; 1262 1263 if (unlikely(!recv_int_page)) 1264 return; 1265 1266 for_each_set_bit(relid, recv_int_page, maxbits) { 1267 void (*callback_fn)(void *context); 1268 struct vmbus_channel *channel; 1269 1270 if (!sync_test_and_clear_bit(relid, recv_int_page)) 1271 continue; 1272 1273 /* Special case - vmbus channel protocol msg */ 1274 if (relid == 0) 1275 continue; 1276 1277 /* 1278 * Pairs with the kfree_rcu() in vmbus_chan_release(). 1279 * Guarantees that the channel data structure doesn't 1280 * get freed while the channel pointer below is being 1281 * dereferenced. 1282 */ 1283 rcu_read_lock(); 1284 1285 /* Find channel based on relid */ 1286 channel = relid2channel(relid); 1287 if (channel == NULL) 1288 goto sched_unlock_rcu; 1289 1290 if (channel->rescind) 1291 goto sched_unlock_rcu; 1292 1293 /* 1294 * Make sure that the ring buffer data structure doesn't get 1295 * freed while we dereference the ring buffer pointer. Test 1296 * for the channel's onchannel_callback being NULL within a 1297 * sched_lock critical section. See also the inline comments 1298 * in vmbus_reset_channel_cb(). 1299 */ 1300 spin_lock(&channel->sched_lock); 1301 1302 callback_fn = channel->onchannel_callback; 1303 if (unlikely(callback_fn == NULL)) 1304 goto sched_unlock; 1305 1306 trace_vmbus_chan_sched(channel); 1307 1308 ++channel->interrupts; 1309 1310 switch (channel->callback_mode) { 1311 case HV_CALL_ISR: 1312 (*callback_fn)(channel->channel_callback_context); 1313 break; 1314 1315 case HV_CALL_BATCHED: 1316 hv_begin_read(&channel->inbound); 1317 fallthrough; 1318 case HV_CALL_DIRECT: 1319 tasklet_schedule(&channel->callback_event); 1320 } 1321 1322 sched_unlock: 1323 spin_unlock(&channel->sched_lock); 1324 sched_unlock_rcu: 1325 rcu_read_unlock(); 1326 } 1327 } 1328 1329 static void vmbus_isr(void) 1330 { 1331 struct hv_per_cpu_context *hv_cpu 1332 = this_cpu_ptr(hv_context.cpu_context); 1333 void *page_addr; 1334 struct hv_message *msg; 1335 1336 vmbus_chan_sched(hv_cpu); 1337 1338 page_addr = hv_cpu->synic_message_page; 1339 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; 1340 1341 /* Check if there are actual msgs to be processed */ 1342 if (msg->header.message_type != HVMSG_NONE) { 1343 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) { 1344 hv_stimer0_isr(); 1345 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED); 1346 } else 1347 tasklet_schedule(&hv_cpu->msg_dpc); 1348 } 1349 1350 add_interrupt_randomness(vmbus_interrupt); 1351 } 1352 1353 static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) 1354 { 1355 vmbus_isr(); 1356 return IRQ_HANDLED; 1357 } 1358 1359 /* 1360 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg 1361 * buffer and call into Hyper-V to transfer the data. 1362 */ 1363 static void hv_kmsg_dump(struct kmsg_dumper *dumper, 1364 enum kmsg_dump_reason reason) 1365 { 1366 struct kmsg_dump_iter iter; 1367 size_t bytes_written; 1368 1369 /* We are only interested in panics. */ 1370 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg)) 1371 return; 1372 1373 /* 1374 * Write dump contents to the page. No need to synchronize; panic should 1375 * be single-threaded. 1376 */ 1377 kmsg_dump_rewind(&iter); 1378 kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE, 1379 &bytes_written); 1380 if (!bytes_written) 1381 return; 1382 /* 1383 * P3 to contain the physical address of the panic page & P4 to 1384 * contain the size of the panic data in that page. Rest of the 1385 * registers are no-op when the NOTIFY_MSG flag is set. 1386 */ 1387 hv_set_register(HV_REGISTER_CRASH_P0, 0); 1388 hv_set_register(HV_REGISTER_CRASH_P1, 0); 1389 hv_set_register(HV_REGISTER_CRASH_P2, 0); 1390 hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page)); 1391 hv_set_register(HV_REGISTER_CRASH_P4, bytes_written); 1392 1393 /* 1394 * Let Hyper-V know there is crash data available along with 1395 * the panic message. 1396 */ 1397 hv_set_register(HV_REGISTER_CRASH_CTL, 1398 (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG)); 1399 } 1400 1401 static struct kmsg_dumper hv_kmsg_dumper = { 1402 .dump = hv_kmsg_dump, 1403 }; 1404 1405 static void hv_kmsg_dump_register(void) 1406 { 1407 int ret; 1408 1409 hv_panic_page = hv_alloc_hyperv_zeroed_page(); 1410 if (!hv_panic_page) { 1411 pr_err("Hyper-V: panic message page memory allocation failed\n"); 1412 return; 1413 } 1414 1415 ret = kmsg_dump_register(&hv_kmsg_dumper); 1416 if (ret) { 1417 pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret); 1418 hv_free_hyperv_page((unsigned long)hv_panic_page); 1419 hv_panic_page = NULL; 1420 } 1421 } 1422 1423 static struct ctl_table_header *hv_ctl_table_hdr; 1424 1425 /* 1426 * sysctl option to allow the user to control whether kmsg data should be 1427 * reported to Hyper-V on panic. 1428 */ 1429 static struct ctl_table hv_ctl_table[] = { 1430 { 1431 .procname = "hyperv_record_panic_msg", 1432 .data = &sysctl_record_panic_msg, 1433 .maxlen = sizeof(int), 1434 .mode = 0644, 1435 .proc_handler = proc_dointvec_minmax, 1436 .extra1 = SYSCTL_ZERO, 1437 .extra2 = SYSCTL_ONE 1438 }, 1439 {} 1440 }; 1441 1442 static struct ctl_table hv_root_table[] = { 1443 { 1444 .procname = "kernel", 1445 .mode = 0555, 1446 .child = hv_ctl_table 1447 }, 1448 {} 1449 }; 1450 1451 /* 1452 * vmbus_bus_init -Main vmbus driver initialization routine. 1453 * 1454 * Here, we 1455 * - initialize the vmbus driver context 1456 * - invoke the vmbus hv main init routine 1457 * - retrieve the channel offers 1458 */ 1459 static int vmbus_bus_init(void) 1460 { 1461 int ret; 1462 1463 ret = hv_init(); 1464 if (ret != 0) { 1465 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret); 1466 return ret; 1467 } 1468 1469 ret = bus_register(&hv_bus); 1470 if (ret) 1471 return ret; 1472 1473 /* 1474 * VMbus interrupts are best modeled as per-cpu interrupts. If 1475 * on an architecture with support for per-cpu IRQs (e.g. ARM64), 1476 * allocate a per-cpu IRQ using standard Linux kernel functionality. 1477 * If not on such an architecture (e.g., x86/x64), then rely on 1478 * code in the arch-specific portion of the code tree to connect 1479 * the VMbus interrupt handler. 1480 */ 1481 1482 if (vmbus_irq == -1) { 1483 hv_setup_vmbus_handler(vmbus_isr); 1484 } else { 1485 vmbus_evt = alloc_percpu(long); 1486 ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr, 1487 "Hyper-V VMbus", vmbus_evt); 1488 if (ret) { 1489 pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d", 1490 vmbus_irq, ret); 1491 free_percpu(vmbus_evt); 1492 goto err_setup; 1493 } 1494 } 1495 1496 ret = hv_synic_alloc(); 1497 if (ret) 1498 goto err_alloc; 1499 1500 /* 1501 * Initialize the per-cpu interrupt state and stimer state. 1502 * Then connect to the host. 1503 */ 1504 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online", 1505 hv_synic_init, hv_synic_cleanup); 1506 if (ret < 0) 1507 goto err_cpuhp; 1508 hyperv_cpuhp_online = ret; 1509 1510 ret = vmbus_connect(); 1511 if (ret) 1512 goto err_connect; 1513 1514 if (hv_is_isolation_supported()) 1515 sysctl_record_panic_msg = 0; 1516 1517 /* 1518 * Only register if the crash MSRs are available 1519 */ 1520 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { 1521 u64 hyperv_crash_ctl; 1522 /* 1523 * Panic message recording (sysctl_record_panic_msg) 1524 * is enabled by default in non-isolated guests and 1525 * disabled by default in isolated guests; the panic 1526 * message recording won't be available in isolated 1527 * guests should the following registration fail. 1528 */ 1529 hv_ctl_table_hdr = register_sysctl_table(hv_root_table); 1530 if (!hv_ctl_table_hdr) 1531 pr_err("Hyper-V: sysctl table register error"); 1532 1533 /* 1534 * Register for panic kmsg callback only if the right 1535 * capability is supported by the hypervisor. 1536 */ 1537 hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL); 1538 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) 1539 hv_kmsg_dump_register(); 1540 1541 register_die_notifier(&hyperv_die_block); 1542 } 1543 1544 /* 1545 * Always register the panic notifier because we need to unload 1546 * the VMbus channel connection to prevent any VMbus 1547 * activity after the VM panics. 1548 */ 1549 atomic_notifier_chain_register(&panic_notifier_list, 1550 &hyperv_panic_block); 1551 1552 vmbus_request_offers(); 1553 1554 return 0; 1555 1556 err_connect: 1557 cpuhp_remove_state(hyperv_cpuhp_online); 1558 err_cpuhp: 1559 hv_synic_free(); 1560 err_alloc: 1561 if (vmbus_irq == -1) { 1562 hv_remove_vmbus_handler(); 1563 } else { 1564 free_percpu_irq(vmbus_irq, vmbus_evt); 1565 free_percpu(vmbus_evt); 1566 } 1567 err_setup: 1568 bus_unregister(&hv_bus); 1569 unregister_sysctl_table(hv_ctl_table_hdr); 1570 hv_ctl_table_hdr = NULL; 1571 return ret; 1572 } 1573 1574 /** 1575 * __vmbus_child_driver_register() - Register a vmbus's driver 1576 * @hv_driver: Pointer to driver structure you want to register 1577 * @owner: owner module of the drv 1578 * @mod_name: module name string 1579 * 1580 * Registers the given driver with Linux through the 'driver_register()' call 1581 * and sets up the hyper-v vmbus handling for this driver. 1582 * It will return the state of the 'driver_register()' call. 1583 * 1584 */ 1585 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name) 1586 { 1587 int ret; 1588 1589 pr_info("registering driver %s\n", hv_driver->name); 1590 1591 ret = vmbus_exists(); 1592 if (ret < 0) 1593 return ret; 1594 1595 hv_driver->driver.name = hv_driver->name; 1596 hv_driver->driver.owner = owner; 1597 hv_driver->driver.mod_name = mod_name; 1598 hv_driver->driver.bus = &hv_bus; 1599 1600 spin_lock_init(&hv_driver->dynids.lock); 1601 INIT_LIST_HEAD(&hv_driver->dynids.list); 1602 1603 ret = driver_register(&hv_driver->driver); 1604 1605 return ret; 1606 } 1607 EXPORT_SYMBOL_GPL(__vmbus_driver_register); 1608 1609 /** 1610 * vmbus_driver_unregister() - Unregister a vmbus's driver 1611 * @hv_driver: Pointer to driver structure you want to 1612 * un-register 1613 * 1614 * Un-register the given driver that was previous registered with a call to 1615 * vmbus_driver_register() 1616 */ 1617 void vmbus_driver_unregister(struct hv_driver *hv_driver) 1618 { 1619 pr_info("unregistering driver %s\n", hv_driver->name); 1620 1621 if (!vmbus_exists()) { 1622 driver_unregister(&hv_driver->driver); 1623 vmbus_free_dynids(hv_driver); 1624 } 1625 } 1626 EXPORT_SYMBOL_GPL(vmbus_driver_unregister); 1627 1628 1629 /* 1630 * Called when last reference to channel is gone. 1631 */ 1632 static void vmbus_chan_release(struct kobject *kobj) 1633 { 1634 struct vmbus_channel *channel 1635 = container_of(kobj, struct vmbus_channel, kobj); 1636 1637 kfree_rcu(channel, rcu); 1638 } 1639 1640 struct vmbus_chan_attribute { 1641 struct attribute attr; 1642 ssize_t (*show)(struct vmbus_channel *chan, char *buf); 1643 ssize_t (*store)(struct vmbus_channel *chan, 1644 const char *buf, size_t count); 1645 }; 1646 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \ 1647 struct vmbus_chan_attribute chan_attr_##_name \ 1648 = __ATTR(_name, _mode, _show, _store) 1649 #define VMBUS_CHAN_ATTR_RW(_name) \ 1650 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name) 1651 #define VMBUS_CHAN_ATTR_RO(_name) \ 1652 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name) 1653 #define VMBUS_CHAN_ATTR_WO(_name) \ 1654 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name) 1655 1656 static ssize_t vmbus_chan_attr_show(struct kobject *kobj, 1657 struct attribute *attr, char *buf) 1658 { 1659 const struct vmbus_chan_attribute *attribute 1660 = container_of(attr, struct vmbus_chan_attribute, attr); 1661 struct vmbus_channel *chan 1662 = container_of(kobj, struct vmbus_channel, kobj); 1663 1664 if (!attribute->show) 1665 return -EIO; 1666 1667 return attribute->show(chan, buf); 1668 } 1669 1670 static ssize_t vmbus_chan_attr_store(struct kobject *kobj, 1671 struct attribute *attr, const char *buf, 1672 size_t count) 1673 { 1674 const struct vmbus_chan_attribute *attribute 1675 = container_of(attr, struct vmbus_chan_attribute, attr); 1676 struct vmbus_channel *chan 1677 = container_of(kobj, struct vmbus_channel, kobj); 1678 1679 if (!attribute->store) 1680 return -EIO; 1681 1682 return attribute->store(chan, buf, count); 1683 } 1684 1685 static const struct sysfs_ops vmbus_chan_sysfs_ops = { 1686 .show = vmbus_chan_attr_show, 1687 .store = vmbus_chan_attr_store, 1688 }; 1689 1690 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf) 1691 { 1692 struct hv_ring_buffer_info *rbi = &channel->outbound; 1693 ssize_t ret; 1694 1695 mutex_lock(&rbi->ring_buffer_mutex); 1696 if (!rbi->ring_buffer) { 1697 mutex_unlock(&rbi->ring_buffer_mutex); 1698 return -EINVAL; 1699 } 1700 1701 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); 1702 mutex_unlock(&rbi->ring_buffer_mutex); 1703 return ret; 1704 } 1705 static VMBUS_CHAN_ATTR_RO(out_mask); 1706 1707 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf) 1708 { 1709 struct hv_ring_buffer_info *rbi = &channel->inbound; 1710 ssize_t ret; 1711 1712 mutex_lock(&rbi->ring_buffer_mutex); 1713 if (!rbi->ring_buffer) { 1714 mutex_unlock(&rbi->ring_buffer_mutex); 1715 return -EINVAL; 1716 } 1717 1718 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); 1719 mutex_unlock(&rbi->ring_buffer_mutex); 1720 return ret; 1721 } 1722 static VMBUS_CHAN_ATTR_RO(in_mask); 1723 1724 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf) 1725 { 1726 struct hv_ring_buffer_info *rbi = &channel->inbound; 1727 ssize_t ret; 1728 1729 mutex_lock(&rbi->ring_buffer_mutex); 1730 if (!rbi->ring_buffer) { 1731 mutex_unlock(&rbi->ring_buffer_mutex); 1732 return -EINVAL; 1733 } 1734 1735 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi)); 1736 mutex_unlock(&rbi->ring_buffer_mutex); 1737 return ret; 1738 } 1739 static VMBUS_CHAN_ATTR_RO(read_avail); 1740 1741 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf) 1742 { 1743 struct hv_ring_buffer_info *rbi = &channel->outbound; 1744 ssize_t ret; 1745 1746 mutex_lock(&rbi->ring_buffer_mutex); 1747 if (!rbi->ring_buffer) { 1748 mutex_unlock(&rbi->ring_buffer_mutex); 1749 return -EINVAL; 1750 } 1751 1752 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi)); 1753 mutex_unlock(&rbi->ring_buffer_mutex); 1754 return ret; 1755 } 1756 static VMBUS_CHAN_ATTR_RO(write_avail); 1757 1758 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf) 1759 { 1760 return sprintf(buf, "%u\n", channel->target_cpu); 1761 } 1762 static ssize_t target_cpu_store(struct vmbus_channel *channel, 1763 const char *buf, size_t count) 1764 { 1765 u32 target_cpu, origin_cpu; 1766 ssize_t ret = count; 1767 1768 if (vmbus_proto_version < VERSION_WIN10_V4_1) 1769 return -EIO; 1770 1771 if (sscanf(buf, "%uu", &target_cpu) != 1) 1772 return -EIO; 1773 1774 /* Validate target_cpu for the cpumask_test_cpu() operation below. */ 1775 if (target_cpu >= nr_cpumask_bits) 1776 return -EINVAL; 1777 1778 if (!cpumask_test_cpu(target_cpu, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ))) 1779 return -EINVAL; 1780 1781 /* No CPUs should come up or down during this. */ 1782 cpus_read_lock(); 1783 1784 if (!cpu_online(target_cpu)) { 1785 cpus_read_unlock(); 1786 return -EINVAL; 1787 } 1788 1789 /* 1790 * Synchronizes target_cpu_store() and channel closure: 1791 * 1792 * { Initially: state = CHANNEL_OPENED } 1793 * 1794 * CPU1 CPU2 1795 * 1796 * [target_cpu_store()] [vmbus_disconnect_ring()] 1797 * 1798 * LOCK channel_mutex LOCK channel_mutex 1799 * LOAD r1 = state LOAD r2 = state 1800 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED) 1801 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN 1802 * [...] SEND CLOSECHANNEL 1803 * UNLOCK channel_mutex UNLOCK channel_mutex 1804 * 1805 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes 1806 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND 1807 * 1808 * Note. The host processes the channel messages "sequentially", in 1809 * the order in which they are received on a per-partition basis. 1810 */ 1811 mutex_lock(&vmbus_connection.channel_mutex); 1812 1813 /* 1814 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels; 1815 * avoid sending the message and fail here for such channels. 1816 */ 1817 if (channel->state != CHANNEL_OPENED_STATE) { 1818 ret = -EIO; 1819 goto cpu_store_unlock; 1820 } 1821 1822 origin_cpu = channel->target_cpu; 1823 if (target_cpu == origin_cpu) 1824 goto cpu_store_unlock; 1825 1826 if (vmbus_send_modifychannel(channel, 1827 hv_cpu_number_to_vp_number(target_cpu))) { 1828 ret = -EIO; 1829 goto cpu_store_unlock; 1830 } 1831 1832 /* 1833 * For version before VERSION_WIN10_V5_3, the following warning holds: 1834 * 1835 * Warning. At this point, there is *no* guarantee that the host will 1836 * have successfully processed the vmbus_send_modifychannel() request. 1837 * See the header comment of vmbus_send_modifychannel() for more info. 1838 * 1839 * Lags in the processing of the above vmbus_send_modifychannel() can 1840 * result in missed interrupts if the "old" target CPU is taken offline 1841 * before Hyper-V starts sending interrupts to the "new" target CPU. 1842 * But apart from this offlining scenario, the code tolerates such 1843 * lags. It will function correctly even if a channel interrupt comes 1844 * in on a CPU that is different from the channel target_cpu value. 1845 */ 1846 1847 channel->target_cpu = target_cpu; 1848 1849 /* See init_vp_index(). */ 1850 if (hv_is_perf_channel(channel)) 1851 hv_update_allocated_cpus(origin_cpu, target_cpu); 1852 1853 /* Currently set only for storvsc channels. */ 1854 if (channel->change_target_cpu_callback) { 1855 (*channel->change_target_cpu_callback)(channel, 1856 origin_cpu, target_cpu); 1857 } 1858 1859 cpu_store_unlock: 1860 mutex_unlock(&vmbus_connection.channel_mutex); 1861 cpus_read_unlock(); 1862 return ret; 1863 } 1864 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store); 1865 1866 static ssize_t channel_pending_show(struct vmbus_channel *channel, 1867 char *buf) 1868 { 1869 return sprintf(buf, "%d\n", 1870 channel_pending(channel, 1871 vmbus_connection.monitor_pages[1])); 1872 } 1873 static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL); 1874 1875 static ssize_t channel_latency_show(struct vmbus_channel *channel, 1876 char *buf) 1877 { 1878 return sprintf(buf, "%d\n", 1879 channel_latency(channel, 1880 vmbus_connection.monitor_pages[1])); 1881 } 1882 static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL); 1883 1884 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf) 1885 { 1886 return sprintf(buf, "%llu\n", channel->interrupts); 1887 } 1888 static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL); 1889 1890 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf) 1891 { 1892 return sprintf(buf, "%llu\n", channel->sig_events); 1893 } 1894 static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL); 1895 1896 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel, 1897 char *buf) 1898 { 1899 return sprintf(buf, "%llu\n", 1900 (unsigned long long)channel->intr_in_full); 1901 } 1902 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL); 1903 1904 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel, 1905 char *buf) 1906 { 1907 return sprintf(buf, "%llu\n", 1908 (unsigned long long)channel->intr_out_empty); 1909 } 1910 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL); 1911 1912 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel, 1913 char *buf) 1914 { 1915 return sprintf(buf, "%llu\n", 1916 (unsigned long long)channel->out_full_first); 1917 } 1918 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL); 1919 1920 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel, 1921 char *buf) 1922 { 1923 return sprintf(buf, "%llu\n", 1924 (unsigned long long)channel->out_full_total); 1925 } 1926 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL); 1927 1928 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel, 1929 char *buf) 1930 { 1931 return sprintf(buf, "%u\n", channel->offermsg.monitorid); 1932 } 1933 static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL); 1934 1935 static ssize_t subchannel_id_show(struct vmbus_channel *channel, 1936 char *buf) 1937 { 1938 return sprintf(buf, "%u\n", 1939 channel->offermsg.offer.sub_channel_index); 1940 } 1941 static VMBUS_CHAN_ATTR_RO(subchannel_id); 1942 1943 static struct attribute *vmbus_chan_attrs[] = { 1944 &chan_attr_out_mask.attr, 1945 &chan_attr_in_mask.attr, 1946 &chan_attr_read_avail.attr, 1947 &chan_attr_write_avail.attr, 1948 &chan_attr_cpu.attr, 1949 &chan_attr_pending.attr, 1950 &chan_attr_latency.attr, 1951 &chan_attr_interrupts.attr, 1952 &chan_attr_events.attr, 1953 &chan_attr_intr_in_full.attr, 1954 &chan_attr_intr_out_empty.attr, 1955 &chan_attr_out_full_first.attr, 1956 &chan_attr_out_full_total.attr, 1957 &chan_attr_monitor_id.attr, 1958 &chan_attr_subchannel_id.attr, 1959 NULL 1960 }; 1961 1962 /* 1963 * Channel-level attribute_group callback function. Returns the permission for 1964 * each attribute, and returns 0 if an attribute is not visible. 1965 */ 1966 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, 1967 struct attribute *attr, int idx) 1968 { 1969 const struct vmbus_channel *channel = 1970 container_of(kobj, struct vmbus_channel, kobj); 1971 1972 /* Hide the monitor attributes if the monitor mechanism is not used. */ 1973 if (!channel->offermsg.monitor_allocated && 1974 (attr == &chan_attr_pending.attr || 1975 attr == &chan_attr_latency.attr || 1976 attr == &chan_attr_monitor_id.attr)) 1977 return 0; 1978 1979 return attr->mode; 1980 } 1981 1982 static struct attribute_group vmbus_chan_group = { 1983 .attrs = vmbus_chan_attrs, 1984 .is_visible = vmbus_chan_attr_is_visible 1985 }; 1986 1987 static struct kobj_type vmbus_chan_ktype = { 1988 .sysfs_ops = &vmbus_chan_sysfs_ops, 1989 .release = vmbus_chan_release, 1990 }; 1991 1992 /* 1993 * vmbus_add_channel_kobj - setup a sub-directory under device/channels 1994 */ 1995 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel) 1996 { 1997 const struct device *device = &dev->device; 1998 struct kobject *kobj = &channel->kobj; 1999 u32 relid = channel->offermsg.child_relid; 2000 int ret; 2001 2002 kobj->kset = dev->channels_kset; 2003 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL, 2004 "%u", relid); 2005 if (ret) { 2006 kobject_put(kobj); 2007 return ret; 2008 } 2009 2010 ret = sysfs_create_group(kobj, &vmbus_chan_group); 2011 2012 if (ret) { 2013 /* 2014 * The calling functions' error handling paths will cleanup the 2015 * empty channel directory. 2016 */ 2017 kobject_put(kobj); 2018 dev_err(device, "Unable to set up channel sysfs files\n"); 2019 return ret; 2020 } 2021 2022 kobject_uevent(kobj, KOBJ_ADD); 2023 2024 return 0; 2025 } 2026 2027 /* 2028 * vmbus_remove_channel_attr_group - remove the channel's attribute group 2029 */ 2030 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel) 2031 { 2032 sysfs_remove_group(&channel->kobj, &vmbus_chan_group); 2033 } 2034 2035 /* 2036 * vmbus_device_create - Creates and registers a new child device 2037 * on the vmbus. 2038 */ 2039 struct hv_device *vmbus_device_create(const guid_t *type, 2040 const guid_t *instance, 2041 struct vmbus_channel *channel) 2042 { 2043 struct hv_device *child_device_obj; 2044 2045 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL); 2046 if (!child_device_obj) { 2047 pr_err("Unable to allocate device object for child device\n"); 2048 return NULL; 2049 } 2050 2051 child_device_obj->channel = channel; 2052 guid_copy(&child_device_obj->dev_type, type); 2053 guid_copy(&child_device_obj->dev_instance, instance); 2054 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */ 2055 2056 return child_device_obj; 2057 } 2058 2059 /* 2060 * vmbus_device_register - Register the child device 2061 */ 2062 int vmbus_device_register(struct hv_device *child_device_obj) 2063 { 2064 struct kobject *kobj = &child_device_obj->device.kobj; 2065 int ret; 2066 2067 dev_set_name(&child_device_obj->device, "%pUl", 2068 &child_device_obj->channel->offermsg.offer.if_instance); 2069 2070 child_device_obj->device.bus = &hv_bus; 2071 child_device_obj->device.parent = &hv_acpi_dev->dev; 2072 child_device_obj->device.release = vmbus_device_release; 2073 2074 child_device_obj->device.dma_parms = &child_device_obj->dma_parms; 2075 child_device_obj->device.dma_mask = &child_device_obj->dma_mask; 2076 dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64)); 2077 2078 /* 2079 * Register with the LDM. This will kick off the driver/device 2080 * binding...which will eventually call vmbus_match() and vmbus_probe() 2081 */ 2082 ret = device_register(&child_device_obj->device); 2083 if (ret) { 2084 pr_err("Unable to register child device\n"); 2085 return ret; 2086 } 2087 2088 child_device_obj->channels_kset = kset_create_and_add("channels", 2089 NULL, kobj); 2090 if (!child_device_obj->channels_kset) { 2091 ret = -ENOMEM; 2092 goto err_dev_unregister; 2093 } 2094 2095 ret = vmbus_add_channel_kobj(child_device_obj, 2096 child_device_obj->channel); 2097 if (ret) { 2098 pr_err("Unable to register primary channeln"); 2099 goto err_kset_unregister; 2100 } 2101 hv_debug_add_dev_dir(child_device_obj); 2102 2103 return 0; 2104 2105 err_kset_unregister: 2106 kset_unregister(child_device_obj->channels_kset); 2107 2108 err_dev_unregister: 2109 device_unregister(&child_device_obj->device); 2110 return ret; 2111 } 2112 2113 /* 2114 * vmbus_device_unregister - Remove the specified child device 2115 * from the vmbus. 2116 */ 2117 void vmbus_device_unregister(struct hv_device *device_obj) 2118 { 2119 pr_debug("child device %s unregistered\n", 2120 dev_name(&device_obj->device)); 2121 2122 kset_unregister(device_obj->channels_kset); 2123 2124 /* 2125 * Kick off the process of unregistering the device. 2126 * This will call vmbus_remove() and eventually vmbus_device_release() 2127 */ 2128 device_unregister(&device_obj->device); 2129 } 2130 2131 2132 /* 2133 * VMBUS is an acpi enumerated device. Get the information we 2134 * need from DSDT. 2135 */ 2136 #define VTPM_BASE_ADDRESS 0xfed40000 2137 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx) 2138 { 2139 resource_size_t start = 0; 2140 resource_size_t end = 0; 2141 struct resource *new_res; 2142 struct resource **old_res = &hyperv_mmio; 2143 struct resource **prev_res = NULL; 2144 struct resource r; 2145 2146 switch (res->type) { 2147 2148 /* 2149 * "Address" descriptors are for bus windows. Ignore 2150 * "memory" descriptors, which are for registers on 2151 * devices. 2152 */ 2153 case ACPI_RESOURCE_TYPE_ADDRESS32: 2154 start = res->data.address32.address.minimum; 2155 end = res->data.address32.address.maximum; 2156 break; 2157 2158 case ACPI_RESOURCE_TYPE_ADDRESS64: 2159 start = res->data.address64.address.minimum; 2160 end = res->data.address64.address.maximum; 2161 break; 2162 2163 /* 2164 * The IRQ information is needed only on ARM64, which Hyper-V 2165 * sets up in the extended format. IRQ information is present 2166 * on x86/x64 in the non-extended format but it is not used by 2167 * Linux. So don't bother checking for the non-extended format. 2168 */ 2169 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: 2170 if (!acpi_dev_resource_interrupt(res, 0, &r)) { 2171 pr_err("Unable to parse Hyper-V ACPI interrupt\n"); 2172 return AE_ERROR; 2173 } 2174 /* ARM64 INTID for VMbus */ 2175 vmbus_interrupt = res->data.extended_irq.interrupts[0]; 2176 /* Linux IRQ number */ 2177 vmbus_irq = r.start; 2178 return AE_OK; 2179 2180 default: 2181 /* Unused resource type */ 2182 return AE_OK; 2183 2184 } 2185 /* 2186 * Ignore ranges that are below 1MB, as they're not 2187 * necessary or useful here. 2188 */ 2189 if (end < 0x100000) 2190 return AE_OK; 2191 2192 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC); 2193 if (!new_res) 2194 return AE_NO_MEMORY; 2195 2196 /* If this range overlaps the virtual TPM, truncate it. */ 2197 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS) 2198 end = VTPM_BASE_ADDRESS; 2199 2200 new_res->name = "hyperv mmio"; 2201 new_res->flags = IORESOURCE_MEM; 2202 new_res->start = start; 2203 new_res->end = end; 2204 2205 /* 2206 * If two ranges are adjacent, merge them. 2207 */ 2208 do { 2209 if (!*old_res) { 2210 *old_res = new_res; 2211 break; 2212 } 2213 2214 if (((*old_res)->end + 1) == new_res->start) { 2215 (*old_res)->end = new_res->end; 2216 kfree(new_res); 2217 break; 2218 } 2219 2220 if ((*old_res)->start == new_res->end + 1) { 2221 (*old_res)->start = new_res->start; 2222 kfree(new_res); 2223 break; 2224 } 2225 2226 if ((*old_res)->start > new_res->end) { 2227 new_res->sibling = *old_res; 2228 if (prev_res) 2229 (*prev_res)->sibling = new_res; 2230 *old_res = new_res; 2231 break; 2232 } 2233 2234 prev_res = old_res; 2235 old_res = &(*old_res)->sibling; 2236 2237 } while (1); 2238 2239 return AE_OK; 2240 } 2241 2242 static int vmbus_acpi_remove(struct acpi_device *device) 2243 { 2244 struct resource *cur_res; 2245 struct resource *next_res; 2246 2247 if (hyperv_mmio) { 2248 if (fb_mmio) { 2249 __release_region(hyperv_mmio, fb_mmio->start, 2250 resource_size(fb_mmio)); 2251 fb_mmio = NULL; 2252 } 2253 2254 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) { 2255 next_res = cur_res->sibling; 2256 kfree(cur_res); 2257 } 2258 } 2259 2260 return 0; 2261 } 2262 2263 static void vmbus_reserve_fb(void) 2264 { 2265 int size; 2266 /* 2267 * Make a claim for the frame buffer in the resource tree under the 2268 * first node, which will be the one below 4GB. The length seems to 2269 * be underreported, particularly in a Generation 1 VM. So start out 2270 * reserving a larger area and make it smaller until it succeeds. 2271 */ 2272 2273 if (screen_info.lfb_base) { 2274 if (efi_enabled(EFI_BOOT)) 2275 size = max_t(__u32, screen_info.lfb_size, 0x800000); 2276 else 2277 size = max_t(__u32, screen_info.lfb_size, 0x4000000); 2278 2279 for (; !fb_mmio && (size >= 0x100000); size >>= 1) { 2280 fb_mmio = __request_region(hyperv_mmio, 2281 screen_info.lfb_base, size, 2282 fb_mmio_name, 0); 2283 } 2284 } 2285 } 2286 2287 /** 2288 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range. 2289 * @new: If successful, supplied a pointer to the 2290 * allocated MMIO space. 2291 * @device_obj: Identifies the caller 2292 * @min: Minimum guest physical address of the 2293 * allocation 2294 * @max: Maximum guest physical address 2295 * @size: Size of the range to be allocated 2296 * @align: Alignment of the range to be allocated 2297 * @fb_overlap_ok: Whether this allocation can be allowed 2298 * to overlap the video frame buffer. 2299 * 2300 * This function walks the resources granted to VMBus by the 2301 * _CRS object in the ACPI namespace underneath the parent 2302 * "bridge" whether that's a root PCI bus in the Generation 1 2303 * case or a Module Device in the Generation 2 case. It then 2304 * attempts to allocate from the global MMIO pool in a way that 2305 * matches the constraints supplied in these parameters and by 2306 * that _CRS. 2307 * 2308 * Return: 0 on success, -errno on failure 2309 */ 2310 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, 2311 resource_size_t min, resource_size_t max, 2312 resource_size_t size, resource_size_t align, 2313 bool fb_overlap_ok) 2314 { 2315 struct resource *iter, *shadow; 2316 resource_size_t range_min, range_max, start; 2317 const char *dev_n = dev_name(&device_obj->device); 2318 int retval; 2319 2320 retval = -ENXIO; 2321 mutex_lock(&hyperv_mmio_lock); 2322 2323 /* 2324 * If overlaps with frame buffers are allowed, then first attempt to 2325 * make the allocation from within the reserved region. Because it 2326 * is already reserved, no shadow allocation is necessary. 2327 */ 2328 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) && 2329 !(max < fb_mmio->start)) { 2330 2331 range_min = fb_mmio->start; 2332 range_max = fb_mmio->end; 2333 start = (range_min + align - 1) & ~(align - 1); 2334 for (; start + size - 1 <= range_max; start += align) { 2335 *new = request_mem_region_exclusive(start, size, dev_n); 2336 if (*new) { 2337 retval = 0; 2338 goto exit; 2339 } 2340 } 2341 } 2342 2343 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2344 if ((iter->start >= max) || (iter->end <= min)) 2345 continue; 2346 2347 range_min = iter->start; 2348 range_max = iter->end; 2349 start = (range_min + align - 1) & ~(align - 1); 2350 for (; start + size - 1 <= range_max; start += align) { 2351 shadow = __request_region(iter, start, size, NULL, 2352 IORESOURCE_BUSY); 2353 if (!shadow) 2354 continue; 2355 2356 *new = request_mem_region_exclusive(start, size, dev_n); 2357 if (*new) { 2358 shadow->name = (char *)*new; 2359 retval = 0; 2360 goto exit; 2361 } 2362 2363 __release_region(iter, start, size); 2364 } 2365 } 2366 2367 exit: 2368 mutex_unlock(&hyperv_mmio_lock); 2369 return retval; 2370 } 2371 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); 2372 2373 /** 2374 * vmbus_free_mmio() - Free a memory-mapped I/O range. 2375 * @start: Base address of region to release. 2376 * @size: Size of the range to be allocated 2377 * 2378 * This function releases anything requested by 2379 * vmbus_mmio_allocate(). 2380 */ 2381 void vmbus_free_mmio(resource_size_t start, resource_size_t size) 2382 { 2383 struct resource *iter; 2384 2385 mutex_lock(&hyperv_mmio_lock); 2386 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2387 if ((iter->start >= start + size) || (iter->end <= start)) 2388 continue; 2389 2390 __release_region(iter, start, size); 2391 } 2392 release_mem_region(start, size); 2393 mutex_unlock(&hyperv_mmio_lock); 2394 2395 } 2396 EXPORT_SYMBOL_GPL(vmbus_free_mmio); 2397 2398 static int vmbus_acpi_add(struct acpi_device *device) 2399 { 2400 acpi_status result; 2401 int ret_val = -ENODEV; 2402 struct acpi_device *ancestor; 2403 2404 hv_acpi_dev = device; 2405 2406 /* 2407 * Older versions of Hyper-V for ARM64 fail to include the _CCA 2408 * method on the top level VMbus device in the DSDT. But devices 2409 * are hardware coherent in all current Hyper-V use cases, so fix 2410 * up the ACPI device to behave as if _CCA is present and indicates 2411 * hardware coherence. 2412 */ 2413 ACPI_COMPANION_SET(&device->dev, device); 2414 if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) && 2415 device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) { 2416 pr_info("No ACPI _CCA found; assuming coherent device I/O\n"); 2417 device->flags.cca_seen = true; 2418 device->flags.coherent_dma = true; 2419 } 2420 2421 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS, 2422 vmbus_walk_resources, NULL); 2423 2424 if (ACPI_FAILURE(result)) 2425 goto acpi_walk_err; 2426 /* 2427 * Some ancestor of the vmbus acpi device (Gen1 or Gen2 2428 * firmware) is the VMOD that has the mmio ranges. Get that. 2429 */ 2430 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) { 2431 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS, 2432 vmbus_walk_resources, NULL); 2433 2434 if (ACPI_FAILURE(result)) 2435 continue; 2436 if (hyperv_mmio) { 2437 vmbus_reserve_fb(); 2438 break; 2439 } 2440 } 2441 ret_val = 0; 2442 2443 acpi_walk_err: 2444 complete(&probe_event); 2445 if (ret_val) 2446 vmbus_acpi_remove(device); 2447 return ret_val; 2448 } 2449 2450 #ifdef CONFIG_PM_SLEEP 2451 static int vmbus_bus_suspend(struct device *dev) 2452 { 2453 struct hv_per_cpu_context *hv_cpu = per_cpu_ptr( 2454 hv_context.cpu_context, VMBUS_CONNECT_CPU); 2455 struct vmbus_channel *channel, *sc; 2456 2457 tasklet_disable(&hv_cpu->msg_dpc); 2458 vmbus_connection.ignore_any_offer_msg = true; 2459 /* The tasklet_enable() takes care of providing a memory barrier */ 2460 tasklet_enable(&hv_cpu->msg_dpc); 2461 2462 /* Drain all the workqueues as we are in suspend */ 2463 drain_workqueue(vmbus_connection.rescind_work_queue); 2464 drain_workqueue(vmbus_connection.work_queue); 2465 drain_workqueue(vmbus_connection.handle_primary_chan_wq); 2466 drain_workqueue(vmbus_connection.handle_sub_chan_wq); 2467 2468 mutex_lock(&vmbus_connection.channel_mutex); 2469 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2470 if (!is_hvsock_channel(channel)) 2471 continue; 2472 2473 vmbus_force_channel_rescinded(channel); 2474 } 2475 mutex_unlock(&vmbus_connection.channel_mutex); 2476 2477 /* 2478 * Wait until all the sub-channels and hv_sock channels have been 2479 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise 2480 * they would conflict with the new sub-channels that will be created 2481 * in the resume path. hv_sock channels should also be destroyed, but 2482 * a hv_sock channel of an established hv_sock connection can not be 2483 * really destroyed since it may still be referenced by the userspace 2484 * application, so we just force the hv_sock channel to be rescinded 2485 * by vmbus_force_channel_rescinded(), and the userspace application 2486 * will thoroughly destroy the channel after hibernation. 2487 * 2488 * Note: the counter nr_chan_close_on_suspend may never go above 0 if 2489 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM. 2490 */ 2491 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0) 2492 wait_for_completion(&vmbus_connection.ready_for_suspend_event); 2493 2494 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) { 2495 pr_err("Can not suspend due to a previous failed resuming\n"); 2496 return -EBUSY; 2497 } 2498 2499 mutex_lock(&vmbus_connection.channel_mutex); 2500 2501 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2502 /* 2503 * Remove the channel from the array of channels and invalidate 2504 * the channel's relid. Upon resume, vmbus_onoffer() will fix 2505 * up the relid (and other fields, if necessary) and add the 2506 * channel back to the array. 2507 */ 2508 vmbus_channel_unmap_relid(channel); 2509 channel->offermsg.child_relid = INVALID_RELID; 2510 2511 if (is_hvsock_channel(channel)) { 2512 if (!channel->rescind) { 2513 pr_err("hv_sock channel not rescinded!\n"); 2514 WARN_ON_ONCE(1); 2515 } 2516 continue; 2517 } 2518 2519 list_for_each_entry(sc, &channel->sc_list, sc_list) { 2520 pr_err("Sub-channel not deleted!\n"); 2521 WARN_ON_ONCE(1); 2522 } 2523 2524 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume); 2525 } 2526 2527 mutex_unlock(&vmbus_connection.channel_mutex); 2528 2529 vmbus_initiate_unload(false); 2530 2531 /* Reset the event for the next resume. */ 2532 reinit_completion(&vmbus_connection.ready_for_resume_event); 2533 2534 return 0; 2535 } 2536 2537 static int vmbus_bus_resume(struct device *dev) 2538 { 2539 struct vmbus_channel_msginfo *msginfo; 2540 size_t msgsize; 2541 int ret; 2542 2543 vmbus_connection.ignore_any_offer_msg = false; 2544 2545 /* 2546 * We only use the 'vmbus_proto_version', which was in use before 2547 * hibernation, to re-negotiate with the host. 2548 */ 2549 if (!vmbus_proto_version) { 2550 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version); 2551 return -EINVAL; 2552 } 2553 2554 msgsize = sizeof(*msginfo) + 2555 sizeof(struct vmbus_channel_initiate_contact); 2556 2557 msginfo = kzalloc(msgsize, GFP_KERNEL); 2558 2559 if (msginfo == NULL) 2560 return -ENOMEM; 2561 2562 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version); 2563 2564 kfree(msginfo); 2565 2566 if (ret != 0) 2567 return ret; 2568 2569 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0); 2570 2571 vmbus_request_offers(); 2572 2573 if (wait_for_completion_timeout( 2574 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0) 2575 pr_err("Some vmbus device is missing after suspending?\n"); 2576 2577 /* Reset the event for the next suspend. */ 2578 reinit_completion(&vmbus_connection.ready_for_suspend_event); 2579 2580 return 0; 2581 } 2582 #else 2583 #define vmbus_bus_suspend NULL 2584 #define vmbus_bus_resume NULL 2585 #endif /* CONFIG_PM_SLEEP */ 2586 2587 static const struct acpi_device_id vmbus_acpi_device_ids[] = { 2588 {"VMBUS", 0}, 2589 {"VMBus", 0}, 2590 {"", 0}, 2591 }; 2592 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids); 2593 2594 /* 2595 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with 2596 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in 2597 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see 2598 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() -> 2599 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's 2600 * resume callback must also run via the "noirq" ops. 2601 * 2602 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment 2603 * earlier in this file before vmbus_pm. 2604 */ 2605 2606 static const struct dev_pm_ops vmbus_bus_pm = { 2607 .suspend_noirq = NULL, 2608 .resume_noirq = NULL, 2609 .freeze_noirq = vmbus_bus_suspend, 2610 .thaw_noirq = vmbus_bus_resume, 2611 .poweroff_noirq = vmbus_bus_suspend, 2612 .restore_noirq = vmbus_bus_resume 2613 }; 2614 2615 static struct acpi_driver vmbus_acpi_driver = { 2616 .name = "vmbus", 2617 .ids = vmbus_acpi_device_ids, 2618 .ops = { 2619 .add = vmbus_acpi_add, 2620 .remove = vmbus_acpi_remove, 2621 }, 2622 .drv.pm = &vmbus_bus_pm, 2623 }; 2624 2625 static void hv_kexec_handler(void) 2626 { 2627 hv_stimer_global_cleanup(); 2628 vmbus_initiate_unload(false); 2629 /* Make sure conn_state is set as hv_synic_cleanup checks for it */ 2630 mb(); 2631 cpuhp_remove_state(hyperv_cpuhp_online); 2632 }; 2633 2634 static void hv_crash_handler(struct pt_regs *regs) 2635 { 2636 int cpu; 2637 2638 vmbus_initiate_unload(true); 2639 /* 2640 * In crash handler we can't schedule synic cleanup for all CPUs, 2641 * doing the cleanup for current CPU only. This should be sufficient 2642 * for kdump. 2643 */ 2644 cpu = smp_processor_id(); 2645 hv_stimer_cleanup(cpu); 2646 hv_synic_disable_regs(cpu); 2647 }; 2648 2649 static int hv_synic_suspend(void) 2650 { 2651 /* 2652 * When we reach here, all the non-boot CPUs have been offlined. 2653 * If we're in a legacy configuration where stimer Direct Mode is 2654 * not enabled, the stimers on the non-boot CPUs have been unbound 2655 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() -> 2656 * hv_stimer_cleanup() -> clockevents_unbind_device(). 2657 * 2658 * hv_synic_suspend() only runs on CPU0 with interrupts disabled. 2659 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because: 2660 * 1) it's unnecessary as interrupts remain disabled between 2661 * syscore_suspend() and syscore_resume(): see create_image() and 2662 * resume_target_kernel() 2663 * 2) the stimer on CPU0 is automatically disabled later by 2664 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ... 2665 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown() 2666 * 3) a warning would be triggered if we call 2667 * clockevents_unbind_device(), which may sleep, in an 2668 * interrupts-disabled context. 2669 */ 2670 2671 hv_synic_disable_regs(0); 2672 2673 return 0; 2674 } 2675 2676 static void hv_synic_resume(void) 2677 { 2678 hv_synic_enable_regs(0); 2679 2680 /* 2681 * Note: we don't need to call hv_stimer_init(0), because the timer 2682 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is 2683 * automatically re-enabled in timekeeping_resume(). 2684 */ 2685 } 2686 2687 /* The callbacks run only on CPU0, with irqs_disabled. */ 2688 static struct syscore_ops hv_synic_syscore_ops = { 2689 .suspend = hv_synic_suspend, 2690 .resume = hv_synic_resume, 2691 }; 2692 2693 static int __init hv_acpi_init(void) 2694 { 2695 int ret, t; 2696 2697 if (!hv_is_hyperv_initialized()) 2698 return -ENODEV; 2699 2700 if (hv_root_partition) 2701 return 0; 2702 2703 init_completion(&probe_event); 2704 2705 /* 2706 * Get ACPI resources first. 2707 */ 2708 ret = acpi_bus_register_driver(&vmbus_acpi_driver); 2709 2710 if (ret) 2711 return ret; 2712 2713 t = wait_for_completion_timeout(&probe_event, 5*HZ); 2714 if (t == 0) { 2715 ret = -ETIMEDOUT; 2716 goto cleanup; 2717 } 2718 2719 /* 2720 * If we're on an architecture with a hardcoded hypervisor 2721 * vector (i.e. x86/x64), override the VMbus interrupt found 2722 * in the ACPI tables. Ensure vmbus_irq is not set since the 2723 * normal Linux IRQ mechanism is not used in this case. 2724 */ 2725 #ifdef HYPERVISOR_CALLBACK_VECTOR 2726 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR; 2727 vmbus_irq = -1; 2728 #endif 2729 2730 hv_debug_init(); 2731 2732 ret = vmbus_bus_init(); 2733 if (ret) 2734 goto cleanup; 2735 2736 hv_setup_kexec_handler(hv_kexec_handler); 2737 hv_setup_crash_handler(hv_crash_handler); 2738 2739 register_syscore_ops(&hv_synic_syscore_ops); 2740 2741 return 0; 2742 2743 cleanup: 2744 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2745 hv_acpi_dev = NULL; 2746 return ret; 2747 } 2748 2749 static void __exit vmbus_exit(void) 2750 { 2751 int cpu; 2752 2753 unregister_syscore_ops(&hv_synic_syscore_ops); 2754 2755 hv_remove_kexec_handler(); 2756 hv_remove_crash_handler(); 2757 vmbus_connection.conn_state = DISCONNECTED; 2758 hv_stimer_global_cleanup(); 2759 vmbus_disconnect(); 2760 if (vmbus_irq == -1) { 2761 hv_remove_vmbus_handler(); 2762 } else { 2763 free_percpu_irq(vmbus_irq, vmbus_evt); 2764 free_percpu(vmbus_evt); 2765 } 2766 for_each_online_cpu(cpu) { 2767 struct hv_per_cpu_context *hv_cpu 2768 = per_cpu_ptr(hv_context.cpu_context, cpu); 2769 2770 tasklet_kill(&hv_cpu->msg_dpc); 2771 } 2772 hv_debug_rm_all_dir(); 2773 2774 vmbus_free_channels(); 2775 kfree(vmbus_connection.channels); 2776 2777 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { 2778 kmsg_dump_unregister(&hv_kmsg_dumper); 2779 unregister_die_notifier(&hyperv_die_block); 2780 } 2781 2782 /* 2783 * The panic notifier is always registered, hence we should 2784 * also unconditionally unregister it here as well. 2785 */ 2786 atomic_notifier_chain_unregister(&panic_notifier_list, 2787 &hyperv_panic_block); 2788 2789 free_page((unsigned long)hv_panic_page); 2790 unregister_sysctl_table(hv_ctl_table_hdr); 2791 hv_ctl_table_hdr = NULL; 2792 bus_unregister(&hv_bus); 2793 2794 cpuhp_remove_state(hyperv_cpuhp_online); 2795 hv_synic_free(); 2796 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2797 } 2798 2799 2800 MODULE_LICENSE("GPL"); 2801 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver"); 2802 2803 subsys_initcall(hv_acpi_init); 2804 module_exit(vmbus_exit); 2805