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