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 <linux/pci.h> 39 #include <clocksource/hyperv_timer.h> 40 #include "hyperv_vmbus.h" 41 42 struct vmbus_dynid { 43 struct list_head node; 44 struct hv_vmbus_device_id id; 45 }; 46 47 static struct acpi_device *hv_acpi_dev; 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 ctx->msg.header = msg_copy.header; 1134 memcpy(&ctx->msg.payload, msg_copy.u.payload, 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_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 = PCI_VENDOR_ID_MICROSOFT; 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 resource_size_t start = 0, size; 2266 struct pci_dev *pdev; 2267 2268 if (efi_enabled(EFI_BOOT)) { 2269 /* Gen2 VM: get FB base from EFI framebuffer */ 2270 start = screen_info.lfb_base; 2271 size = max_t(__u32, screen_info.lfb_size, 0x800000); 2272 } else { 2273 /* Gen1 VM: get FB base from PCI */ 2274 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT, 2275 PCI_DEVICE_ID_HYPERV_VIDEO, NULL); 2276 if (!pdev) 2277 return; 2278 2279 if (pdev->resource[0].flags & IORESOURCE_MEM) { 2280 start = pci_resource_start(pdev, 0); 2281 size = pci_resource_len(pdev, 0); 2282 } 2283 2284 /* 2285 * Release the PCI device so hyperv_drm or hyperv_fb driver can 2286 * grab it later. 2287 */ 2288 pci_dev_put(pdev); 2289 } 2290 2291 if (!start) 2292 return; 2293 2294 /* 2295 * Make a claim for the frame buffer in the resource tree under the 2296 * first node, which will be the one below 4GB. The length seems to 2297 * be underreported, particularly in a Generation 1 VM. So start out 2298 * reserving a larger area and make it smaller until it succeeds. 2299 */ 2300 for (; !fb_mmio && (size >= 0x100000); size >>= 1) 2301 fb_mmio = __request_region(hyperv_mmio, start, size, fb_mmio_name, 0); 2302 } 2303 2304 /** 2305 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range. 2306 * @new: If successful, supplied a pointer to the 2307 * allocated MMIO space. 2308 * @device_obj: Identifies the caller 2309 * @min: Minimum guest physical address of the 2310 * allocation 2311 * @max: Maximum guest physical address 2312 * @size: Size of the range to be allocated 2313 * @align: Alignment of the range to be allocated 2314 * @fb_overlap_ok: Whether this allocation can be allowed 2315 * to overlap the video frame buffer. 2316 * 2317 * This function walks the resources granted to VMBus by the 2318 * _CRS object in the ACPI namespace underneath the parent 2319 * "bridge" whether that's a root PCI bus in the Generation 1 2320 * case or a Module Device in the Generation 2 case. It then 2321 * attempts to allocate from the global MMIO pool in a way that 2322 * matches the constraints supplied in these parameters and by 2323 * that _CRS. 2324 * 2325 * Return: 0 on success, -errno on failure 2326 */ 2327 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, 2328 resource_size_t min, resource_size_t max, 2329 resource_size_t size, resource_size_t align, 2330 bool fb_overlap_ok) 2331 { 2332 struct resource *iter, *shadow; 2333 resource_size_t range_min, range_max, start, end; 2334 const char *dev_n = dev_name(&device_obj->device); 2335 int retval; 2336 2337 retval = -ENXIO; 2338 mutex_lock(&hyperv_mmio_lock); 2339 2340 /* 2341 * If overlaps with frame buffers are allowed, then first attempt to 2342 * make the allocation from within the reserved region. Because it 2343 * is already reserved, no shadow allocation is necessary. 2344 */ 2345 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) && 2346 !(max < fb_mmio->start)) { 2347 2348 range_min = fb_mmio->start; 2349 range_max = fb_mmio->end; 2350 start = (range_min + align - 1) & ~(align - 1); 2351 for (; start + size - 1 <= range_max; start += align) { 2352 *new = request_mem_region_exclusive(start, size, dev_n); 2353 if (*new) { 2354 retval = 0; 2355 goto exit; 2356 } 2357 } 2358 } 2359 2360 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2361 if ((iter->start >= max) || (iter->end <= min)) 2362 continue; 2363 2364 range_min = iter->start; 2365 range_max = iter->end; 2366 start = (range_min + align - 1) & ~(align - 1); 2367 for (; start + size - 1 <= range_max; start += align) { 2368 end = start + size - 1; 2369 2370 /* Skip the whole fb_mmio region if not fb_overlap_ok */ 2371 if (!fb_overlap_ok && fb_mmio && 2372 (((start >= fb_mmio->start) && (start <= fb_mmio->end)) || 2373 ((end >= fb_mmio->start) && (end <= fb_mmio->end)))) 2374 continue; 2375 2376 shadow = __request_region(iter, start, size, NULL, 2377 IORESOURCE_BUSY); 2378 if (!shadow) 2379 continue; 2380 2381 *new = request_mem_region_exclusive(start, size, dev_n); 2382 if (*new) { 2383 shadow->name = (char *)*new; 2384 retval = 0; 2385 goto exit; 2386 } 2387 2388 __release_region(iter, start, size); 2389 } 2390 } 2391 2392 exit: 2393 mutex_unlock(&hyperv_mmio_lock); 2394 return retval; 2395 } 2396 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); 2397 2398 /** 2399 * vmbus_free_mmio() - Free a memory-mapped I/O range. 2400 * @start: Base address of region to release. 2401 * @size: Size of the range to be allocated 2402 * 2403 * This function releases anything requested by 2404 * vmbus_mmio_allocate(). 2405 */ 2406 void vmbus_free_mmio(resource_size_t start, resource_size_t size) 2407 { 2408 struct resource *iter; 2409 2410 mutex_lock(&hyperv_mmio_lock); 2411 for (iter = hyperv_mmio; iter; iter = iter->sibling) { 2412 if ((iter->start >= start + size) || (iter->end <= start)) 2413 continue; 2414 2415 __release_region(iter, start, size); 2416 } 2417 release_mem_region(start, size); 2418 mutex_unlock(&hyperv_mmio_lock); 2419 2420 } 2421 EXPORT_SYMBOL_GPL(vmbus_free_mmio); 2422 2423 static int vmbus_acpi_add(struct acpi_device *device) 2424 { 2425 acpi_status result; 2426 int ret_val = -ENODEV; 2427 struct acpi_device *ancestor; 2428 2429 hv_acpi_dev = device; 2430 2431 /* 2432 * Older versions of Hyper-V for ARM64 fail to include the _CCA 2433 * method on the top level VMbus device in the DSDT. But devices 2434 * are hardware coherent in all current Hyper-V use cases, so fix 2435 * up the ACPI device to behave as if _CCA is present and indicates 2436 * hardware coherence. 2437 */ 2438 ACPI_COMPANION_SET(&device->dev, device); 2439 if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) && 2440 device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) { 2441 pr_info("No ACPI _CCA found; assuming coherent device I/O\n"); 2442 device->flags.cca_seen = true; 2443 device->flags.coherent_dma = true; 2444 } 2445 2446 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS, 2447 vmbus_walk_resources, NULL); 2448 2449 if (ACPI_FAILURE(result)) 2450 goto acpi_walk_err; 2451 /* 2452 * Some ancestor of the vmbus acpi device (Gen1 or Gen2 2453 * firmware) is the VMOD that has the mmio ranges. Get that. 2454 */ 2455 for (ancestor = acpi_dev_parent(device); ancestor; 2456 ancestor = acpi_dev_parent(ancestor)) { 2457 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS, 2458 vmbus_walk_resources, NULL); 2459 2460 if (ACPI_FAILURE(result)) 2461 continue; 2462 if (hyperv_mmio) { 2463 vmbus_reserve_fb(); 2464 break; 2465 } 2466 } 2467 ret_val = 0; 2468 2469 acpi_walk_err: 2470 if (ret_val) 2471 vmbus_acpi_remove(device); 2472 return ret_val; 2473 } 2474 2475 #ifdef CONFIG_PM_SLEEP 2476 static int vmbus_bus_suspend(struct device *dev) 2477 { 2478 struct hv_per_cpu_context *hv_cpu = per_cpu_ptr( 2479 hv_context.cpu_context, VMBUS_CONNECT_CPU); 2480 struct vmbus_channel *channel, *sc; 2481 2482 tasklet_disable(&hv_cpu->msg_dpc); 2483 vmbus_connection.ignore_any_offer_msg = true; 2484 /* The tasklet_enable() takes care of providing a memory barrier */ 2485 tasklet_enable(&hv_cpu->msg_dpc); 2486 2487 /* Drain all the workqueues as we are in suspend */ 2488 drain_workqueue(vmbus_connection.rescind_work_queue); 2489 drain_workqueue(vmbus_connection.work_queue); 2490 drain_workqueue(vmbus_connection.handle_primary_chan_wq); 2491 drain_workqueue(vmbus_connection.handle_sub_chan_wq); 2492 2493 mutex_lock(&vmbus_connection.channel_mutex); 2494 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2495 if (!is_hvsock_channel(channel)) 2496 continue; 2497 2498 vmbus_force_channel_rescinded(channel); 2499 } 2500 mutex_unlock(&vmbus_connection.channel_mutex); 2501 2502 /* 2503 * Wait until all the sub-channels and hv_sock channels have been 2504 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise 2505 * they would conflict with the new sub-channels that will be created 2506 * in the resume path. hv_sock channels should also be destroyed, but 2507 * a hv_sock channel of an established hv_sock connection can not be 2508 * really destroyed since it may still be referenced by the userspace 2509 * application, so we just force the hv_sock channel to be rescinded 2510 * by vmbus_force_channel_rescinded(), and the userspace application 2511 * will thoroughly destroy the channel after hibernation. 2512 * 2513 * Note: the counter nr_chan_close_on_suspend may never go above 0 if 2514 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM. 2515 */ 2516 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0) 2517 wait_for_completion(&vmbus_connection.ready_for_suspend_event); 2518 2519 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) { 2520 pr_err("Can not suspend due to a previous failed resuming\n"); 2521 return -EBUSY; 2522 } 2523 2524 mutex_lock(&vmbus_connection.channel_mutex); 2525 2526 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 2527 /* 2528 * Remove the channel from the array of channels and invalidate 2529 * the channel's relid. Upon resume, vmbus_onoffer() will fix 2530 * up the relid (and other fields, if necessary) and add the 2531 * channel back to the array. 2532 */ 2533 vmbus_channel_unmap_relid(channel); 2534 channel->offermsg.child_relid = INVALID_RELID; 2535 2536 if (is_hvsock_channel(channel)) { 2537 if (!channel->rescind) { 2538 pr_err("hv_sock channel not rescinded!\n"); 2539 WARN_ON_ONCE(1); 2540 } 2541 continue; 2542 } 2543 2544 list_for_each_entry(sc, &channel->sc_list, sc_list) { 2545 pr_err("Sub-channel not deleted!\n"); 2546 WARN_ON_ONCE(1); 2547 } 2548 2549 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume); 2550 } 2551 2552 mutex_unlock(&vmbus_connection.channel_mutex); 2553 2554 vmbus_initiate_unload(false); 2555 2556 /* Reset the event for the next resume. */ 2557 reinit_completion(&vmbus_connection.ready_for_resume_event); 2558 2559 return 0; 2560 } 2561 2562 static int vmbus_bus_resume(struct device *dev) 2563 { 2564 struct vmbus_channel_msginfo *msginfo; 2565 size_t msgsize; 2566 int ret; 2567 2568 vmbus_connection.ignore_any_offer_msg = false; 2569 2570 /* 2571 * We only use the 'vmbus_proto_version', which was in use before 2572 * hibernation, to re-negotiate with the host. 2573 */ 2574 if (!vmbus_proto_version) { 2575 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version); 2576 return -EINVAL; 2577 } 2578 2579 msgsize = sizeof(*msginfo) + 2580 sizeof(struct vmbus_channel_initiate_contact); 2581 2582 msginfo = kzalloc(msgsize, GFP_KERNEL); 2583 2584 if (msginfo == NULL) 2585 return -ENOMEM; 2586 2587 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version); 2588 2589 kfree(msginfo); 2590 2591 if (ret != 0) 2592 return ret; 2593 2594 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0); 2595 2596 vmbus_request_offers(); 2597 2598 if (wait_for_completion_timeout( 2599 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0) 2600 pr_err("Some vmbus device is missing after suspending?\n"); 2601 2602 /* Reset the event for the next suspend. */ 2603 reinit_completion(&vmbus_connection.ready_for_suspend_event); 2604 2605 return 0; 2606 } 2607 #else 2608 #define vmbus_bus_suspend NULL 2609 #define vmbus_bus_resume NULL 2610 #endif /* CONFIG_PM_SLEEP */ 2611 2612 static const struct acpi_device_id vmbus_acpi_device_ids[] = { 2613 {"VMBUS", 0}, 2614 {"VMBus", 0}, 2615 {"", 0}, 2616 }; 2617 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids); 2618 2619 /* 2620 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with 2621 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in 2622 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see 2623 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() -> 2624 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's 2625 * resume callback must also run via the "noirq" ops. 2626 * 2627 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment 2628 * earlier in this file before vmbus_pm. 2629 */ 2630 2631 static const struct dev_pm_ops vmbus_bus_pm = { 2632 .suspend_noirq = NULL, 2633 .resume_noirq = NULL, 2634 .freeze_noirq = vmbus_bus_suspend, 2635 .thaw_noirq = vmbus_bus_resume, 2636 .poweroff_noirq = vmbus_bus_suspend, 2637 .restore_noirq = vmbus_bus_resume 2638 }; 2639 2640 static struct acpi_driver vmbus_acpi_driver = { 2641 .name = "vmbus", 2642 .ids = vmbus_acpi_device_ids, 2643 .ops = { 2644 .add = vmbus_acpi_add, 2645 .remove = vmbus_acpi_remove, 2646 }, 2647 .drv.pm = &vmbus_bus_pm, 2648 .drv.probe_type = PROBE_FORCE_SYNCHRONOUS, 2649 }; 2650 2651 static void hv_kexec_handler(void) 2652 { 2653 hv_stimer_global_cleanup(); 2654 vmbus_initiate_unload(false); 2655 /* Make sure conn_state is set as hv_synic_cleanup checks for it */ 2656 mb(); 2657 cpuhp_remove_state(hyperv_cpuhp_online); 2658 }; 2659 2660 static void hv_crash_handler(struct pt_regs *regs) 2661 { 2662 int cpu; 2663 2664 vmbus_initiate_unload(true); 2665 /* 2666 * In crash handler we can't schedule synic cleanup for all CPUs, 2667 * doing the cleanup for current CPU only. This should be sufficient 2668 * for kdump. 2669 */ 2670 cpu = smp_processor_id(); 2671 hv_stimer_cleanup(cpu); 2672 hv_synic_disable_regs(cpu); 2673 }; 2674 2675 static int hv_synic_suspend(void) 2676 { 2677 /* 2678 * When we reach here, all the non-boot CPUs have been offlined. 2679 * If we're in a legacy configuration where stimer Direct Mode is 2680 * not enabled, the stimers on the non-boot CPUs have been unbound 2681 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() -> 2682 * hv_stimer_cleanup() -> clockevents_unbind_device(). 2683 * 2684 * hv_synic_suspend() only runs on CPU0 with interrupts disabled. 2685 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because: 2686 * 1) it's unnecessary as interrupts remain disabled between 2687 * syscore_suspend() and syscore_resume(): see create_image() and 2688 * resume_target_kernel() 2689 * 2) the stimer on CPU0 is automatically disabled later by 2690 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ... 2691 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown() 2692 * 3) a warning would be triggered if we call 2693 * clockevents_unbind_device(), which may sleep, in an 2694 * interrupts-disabled context. 2695 */ 2696 2697 hv_synic_disable_regs(0); 2698 2699 return 0; 2700 } 2701 2702 static void hv_synic_resume(void) 2703 { 2704 hv_synic_enable_regs(0); 2705 2706 /* 2707 * Note: we don't need to call hv_stimer_init(0), because the timer 2708 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is 2709 * automatically re-enabled in timekeeping_resume(). 2710 */ 2711 } 2712 2713 /* The callbacks run only on CPU0, with irqs_disabled. */ 2714 static struct syscore_ops hv_synic_syscore_ops = { 2715 .suspend = hv_synic_suspend, 2716 .resume = hv_synic_resume, 2717 }; 2718 2719 static int __init hv_acpi_init(void) 2720 { 2721 int ret; 2722 2723 if (!hv_is_hyperv_initialized()) 2724 return -ENODEV; 2725 2726 if (hv_root_partition) 2727 return 0; 2728 2729 /* 2730 * Get ACPI resources first. 2731 */ 2732 ret = acpi_bus_register_driver(&vmbus_acpi_driver); 2733 2734 if (ret) 2735 return ret; 2736 2737 if (!hv_acpi_dev) { 2738 ret = -ENODEV; 2739 goto cleanup; 2740 } 2741 2742 /* 2743 * If we're on an architecture with a hardcoded hypervisor 2744 * vector (i.e. x86/x64), override the VMbus interrupt found 2745 * in the ACPI tables. Ensure vmbus_irq is not set since the 2746 * normal Linux IRQ mechanism is not used in this case. 2747 */ 2748 #ifdef HYPERVISOR_CALLBACK_VECTOR 2749 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR; 2750 vmbus_irq = -1; 2751 #endif 2752 2753 hv_debug_init(); 2754 2755 ret = vmbus_bus_init(); 2756 if (ret) 2757 goto cleanup; 2758 2759 hv_setup_kexec_handler(hv_kexec_handler); 2760 hv_setup_crash_handler(hv_crash_handler); 2761 2762 register_syscore_ops(&hv_synic_syscore_ops); 2763 2764 return 0; 2765 2766 cleanup: 2767 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2768 hv_acpi_dev = NULL; 2769 return ret; 2770 } 2771 2772 static void __exit vmbus_exit(void) 2773 { 2774 int cpu; 2775 2776 unregister_syscore_ops(&hv_synic_syscore_ops); 2777 2778 hv_remove_kexec_handler(); 2779 hv_remove_crash_handler(); 2780 vmbus_connection.conn_state = DISCONNECTED; 2781 hv_stimer_global_cleanup(); 2782 vmbus_disconnect(); 2783 if (vmbus_irq == -1) { 2784 hv_remove_vmbus_handler(); 2785 } else { 2786 free_percpu_irq(vmbus_irq, vmbus_evt); 2787 free_percpu(vmbus_evt); 2788 } 2789 for_each_online_cpu(cpu) { 2790 struct hv_per_cpu_context *hv_cpu 2791 = per_cpu_ptr(hv_context.cpu_context, cpu); 2792 2793 tasklet_kill(&hv_cpu->msg_dpc); 2794 } 2795 hv_debug_rm_all_dir(); 2796 2797 vmbus_free_channels(); 2798 kfree(vmbus_connection.channels); 2799 2800 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { 2801 kmsg_dump_unregister(&hv_kmsg_dumper); 2802 unregister_die_notifier(&hyperv_die_block); 2803 } 2804 2805 /* 2806 * The panic notifier is always registered, hence we should 2807 * also unconditionally unregister it here as well. 2808 */ 2809 atomic_notifier_chain_unregister(&panic_notifier_list, 2810 &hyperv_panic_block); 2811 2812 free_page((unsigned long)hv_panic_page); 2813 unregister_sysctl_table(hv_ctl_table_hdr); 2814 hv_ctl_table_hdr = NULL; 2815 bus_unregister(&hv_bus); 2816 2817 cpuhp_remove_state(hyperv_cpuhp_online); 2818 hv_synic_free(); 2819 acpi_bus_unregister_driver(&vmbus_acpi_driver); 2820 } 2821 2822 2823 MODULE_LICENSE("GPL"); 2824 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver"); 2825 2826 subsys_initcall(hv_acpi_init); 2827 module_exit(vmbus_exit); 2828