1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2009, Microsoft Corporation.
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 * K. Y. Srinivasan <kys@microsoft.com>
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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"
39 struct list_head node;
40 struct hv_vmbus_device_id id;
43 static struct acpi_device *hv_acpi_dev;
45 static struct completion probe_event;
47 static int hyperv_cpuhp_online;
49 static void *hv_panic_page;
51 static long __percpu *vmbus_evt;
53 /* Values parsed from ACPI DSDT */
58 * Boolean to control whether to report panic messages over Hyper-V.
60 * It can be set via /proc/sys/kernel/hyperv_record_panic_msg
62 static int sysctl_record_panic_msg = 1;
64 static int hyperv_report_reg(void)
66 return !sysctl_record_panic_msg || !hv_panic_page;
69 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
74 vmbus_initiate_unload(true);
77 * Hyper-V should be notified only once about a panic. If we will be
78 * doing hyperv_report_panic_msg() later with kmsg data, don't do
79 * the notification here.
81 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
82 && hyperv_report_reg()) {
83 regs = current_pt_regs();
84 hyperv_report_panic(regs, val, false);
89 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
92 struct die_args *die = args;
93 struct pt_regs *regs = die->regs;
95 /* Don't notify Hyper-V if the die event is other than oops */
100 * Hyper-V should be notified only once about a panic. If we will be
101 * doing hyperv_report_panic_msg() later with kmsg data, don't do
102 * the notification here.
104 if (hyperv_report_reg())
105 hyperv_report_panic(regs, val, true);
109 static struct notifier_block hyperv_die_block = {
110 .notifier_call = hyperv_die_event,
112 static struct notifier_block hyperv_panic_block = {
113 .notifier_call = hyperv_panic_event,
116 static const char *fb_mmio_name = "fb_range";
117 static struct resource *fb_mmio;
118 static struct resource *hyperv_mmio;
119 static DEFINE_MUTEX(hyperv_mmio_lock);
121 static int vmbus_exists(void)
123 if (hv_acpi_dev == NULL)
129 static u8 channel_monitor_group(const struct vmbus_channel *channel)
131 return (u8)channel->offermsg.monitorid / 32;
134 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
136 return (u8)channel->offermsg.monitorid % 32;
139 static u32 channel_pending(const struct vmbus_channel *channel,
140 const struct hv_monitor_page *monitor_page)
142 u8 monitor_group = channel_monitor_group(channel);
144 return monitor_page->trigger_group[monitor_group].pending;
147 static u32 channel_latency(const struct vmbus_channel *channel,
148 const struct hv_monitor_page *monitor_page)
150 u8 monitor_group = channel_monitor_group(channel);
151 u8 monitor_offset = channel_monitor_offset(channel);
153 return monitor_page->latency[monitor_group][monitor_offset];
156 static u32 channel_conn_id(struct vmbus_channel *channel,
157 struct hv_monitor_page *monitor_page)
159 u8 monitor_group = channel_monitor_group(channel);
160 u8 monitor_offset = channel_monitor_offset(channel);
162 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
165 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
168 struct hv_device *hv_dev = device_to_hv_device(dev);
170 if (!hv_dev->channel)
172 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
174 static DEVICE_ATTR_RO(id);
176 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
179 struct hv_device *hv_dev = device_to_hv_device(dev);
181 if (!hv_dev->channel)
183 return sprintf(buf, "%d\n", hv_dev->channel->state);
185 static DEVICE_ATTR_RO(state);
187 static ssize_t monitor_id_show(struct device *dev,
188 struct device_attribute *dev_attr, char *buf)
190 struct hv_device *hv_dev = device_to_hv_device(dev);
192 if (!hv_dev->channel)
194 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
196 static DEVICE_ATTR_RO(monitor_id);
198 static ssize_t class_id_show(struct device *dev,
199 struct device_attribute *dev_attr, char *buf)
201 struct hv_device *hv_dev = device_to_hv_device(dev);
203 if (!hv_dev->channel)
205 return sprintf(buf, "{%pUl}\n",
206 &hv_dev->channel->offermsg.offer.if_type);
208 static DEVICE_ATTR_RO(class_id);
210 static ssize_t device_id_show(struct device *dev,
211 struct device_attribute *dev_attr, char *buf)
213 struct hv_device *hv_dev = device_to_hv_device(dev);
215 if (!hv_dev->channel)
217 return sprintf(buf, "{%pUl}\n",
218 &hv_dev->channel->offermsg.offer.if_instance);
220 static DEVICE_ATTR_RO(device_id);
222 static ssize_t modalias_show(struct device *dev,
223 struct device_attribute *dev_attr, char *buf)
225 struct hv_device *hv_dev = device_to_hv_device(dev);
227 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
229 static DEVICE_ATTR_RO(modalias);
232 static ssize_t numa_node_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
235 struct hv_device *hv_dev = device_to_hv_device(dev);
237 if (!hv_dev->channel)
240 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
242 static DEVICE_ATTR_RO(numa_node);
245 static ssize_t server_monitor_pending_show(struct device *dev,
246 struct device_attribute *dev_attr,
249 struct hv_device *hv_dev = device_to_hv_device(dev);
251 if (!hv_dev->channel)
253 return sprintf(buf, "%d\n",
254 channel_pending(hv_dev->channel,
255 vmbus_connection.monitor_pages[0]));
257 static DEVICE_ATTR_RO(server_monitor_pending);
259 static ssize_t client_monitor_pending_show(struct device *dev,
260 struct device_attribute *dev_attr,
263 struct hv_device *hv_dev = device_to_hv_device(dev);
265 if (!hv_dev->channel)
267 return sprintf(buf, "%d\n",
268 channel_pending(hv_dev->channel,
269 vmbus_connection.monitor_pages[1]));
271 static DEVICE_ATTR_RO(client_monitor_pending);
273 static ssize_t server_monitor_latency_show(struct device *dev,
274 struct device_attribute *dev_attr,
277 struct hv_device *hv_dev = device_to_hv_device(dev);
279 if (!hv_dev->channel)
281 return sprintf(buf, "%d\n",
282 channel_latency(hv_dev->channel,
283 vmbus_connection.monitor_pages[0]));
285 static DEVICE_ATTR_RO(server_monitor_latency);
287 static ssize_t client_monitor_latency_show(struct device *dev,
288 struct device_attribute *dev_attr,
291 struct hv_device *hv_dev = device_to_hv_device(dev);
293 if (!hv_dev->channel)
295 return sprintf(buf, "%d\n",
296 channel_latency(hv_dev->channel,
297 vmbus_connection.monitor_pages[1]));
299 static DEVICE_ATTR_RO(client_monitor_latency);
301 static ssize_t server_monitor_conn_id_show(struct device *dev,
302 struct device_attribute *dev_attr,
305 struct hv_device *hv_dev = device_to_hv_device(dev);
307 if (!hv_dev->channel)
309 return sprintf(buf, "%d\n",
310 channel_conn_id(hv_dev->channel,
311 vmbus_connection.monitor_pages[0]));
313 static DEVICE_ATTR_RO(server_monitor_conn_id);
315 static ssize_t client_monitor_conn_id_show(struct device *dev,
316 struct device_attribute *dev_attr,
319 struct hv_device *hv_dev = device_to_hv_device(dev);
321 if (!hv_dev->channel)
323 return sprintf(buf, "%d\n",
324 channel_conn_id(hv_dev->channel,
325 vmbus_connection.monitor_pages[1]));
327 static DEVICE_ATTR_RO(client_monitor_conn_id);
329 static ssize_t out_intr_mask_show(struct device *dev,
330 struct device_attribute *dev_attr, char *buf)
332 struct hv_device *hv_dev = device_to_hv_device(dev);
333 struct hv_ring_buffer_debug_info outbound;
336 if (!hv_dev->channel)
339 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
344 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
346 static DEVICE_ATTR_RO(out_intr_mask);
348 static ssize_t out_read_index_show(struct device *dev,
349 struct device_attribute *dev_attr, char *buf)
351 struct hv_device *hv_dev = device_to_hv_device(dev);
352 struct hv_ring_buffer_debug_info outbound;
355 if (!hv_dev->channel)
358 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
362 return sprintf(buf, "%d\n", outbound.current_read_index);
364 static DEVICE_ATTR_RO(out_read_index);
366 static ssize_t out_write_index_show(struct device *dev,
367 struct device_attribute *dev_attr,
370 struct hv_device *hv_dev = device_to_hv_device(dev);
371 struct hv_ring_buffer_debug_info outbound;
374 if (!hv_dev->channel)
377 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
381 return sprintf(buf, "%d\n", outbound.current_write_index);
383 static DEVICE_ATTR_RO(out_write_index);
385 static ssize_t out_read_bytes_avail_show(struct device *dev,
386 struct device_attribute *dev_attr,
389 struct hv_device *hv_dev = device_to_hv_device(dev);
390 struct hv_ring_buffer_debug_info outbound;
393 if (!hv_dev->channel)
396 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
400 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
402 static DEVICE_ATTR_RO(out_read_bytes_avail);
404 static ssize_t out_write_bytes_avail_show(struct device *dev,
405 struct device_attribute *dev_attr,
408 struct hv_device *hv_dev = device_to_hv_device(dev);
409 struct hv_ring_buffer_debug_info outbound;
412 if (!hv_dev->channel)
415 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
419 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
421 static DEVICE_ATTR_RO(out_write_bytes_avail);
423 static ssize_t in_intr_mask_show(struct device *dev,
424 struct device_attribute *dev_attr, char *buf)
426 struct hv_device *hv_dev = device_to_hv_device(dev);
427 struct hv_ring_buffer_debug_info inbound;
430 if (!hv_dev->channel)
433 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
437 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
439 static DEVICE_ATTR_RO(in_intr_mask);
441 static ssize_t in_read_index_show(struct device *dev,
442 struct device_attribute *dev_attr, char *buf)
444 struct hv_device *hv_dev = device_to_hv_device(dev);
445 struct hv_ring_buffer_debug_info inbound;
448 if (!hv_dev->channel)
451 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
455 return sprintf(buf, "%d\n", inbound.current_read_index);
457 static DEVICE_ATTR_RO(in_read_index);
459 static ssize_t in_write_index_show(struct device *dev,
460 struct device_attribute *dev_attr, char *buf)
462 struct hv_device *hv_dev = device_to_hv_device(dev);
463 struct hv_ring_buffer_debug_info inbound;
466 if (!hv_dev->channel)
469 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
473 return sprintf(buf, "%d\n", inbound.current_write_index);
475 static DEVICE_ATTR_RO(in_write_index);
477 static ssize_t in_read_bytes_avail_show(struct device *dev,
478 struct device_attribute *dev_attr,
481 struct hv_device *hv_dev = device_to_hv_device(dev);
482 struct hv_ring_buffer_debug_info inbound;
485 if (!hv_dev->channel)
488 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
492 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
494 static DEVICE_ATTR_RO(in_read_bytes_avail);
496 static ssize_t in_write_bytes_avail_show(struct device *dev,
497 struct device_attribute *dev_attr,
500 struct hv_device *hv_dev = device_to_hv_device(dev);
501 struct hv_ring_buffer_debug_info inbound;
504 if (!hv_dev->channel)
507 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
511 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
513 static DEVICE_ATTR_RO(in_write_bytes_avail);
515 static ssize_t channel_vp_mapping_show(struct device *dev,
516 struct device_attribute *dev_attr,
519 struct hv_device *hv_dev = device_to_hv_device(dev);
520 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
521 int buf_size = PAGE_SIZE, n_written, tot_written;
522 struct list_head *cur;
527 mutex_lock(&vmbus_connection.channel_mutex);
529 tot_written = snprintf(buf, buf_size, "%u:%u\n",
530 channel->offermsg.child_relid, channel->target_cpu);
532 list_for_each(cur, &channel->sc_list) {
533 if (tot_written >= buf_size - 1)
536 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
537 n_written = scnprintf(buf + tot_written,
538 buf_size - tot_written,
540 cur_sc->offermsg.child_relid,
542 tot_written += n_written;
545 mutex_unlock(&vmbus_connection.channel_mutex);
549 static DEVICE_ATTR_RO(channel_vp_mapping);
551 static ssize_t vendor_show(struct device *dev,
552 struct device_attribute *dev_attr,
555 struct hv_device *hv_dev = device_to_hv_device(dev);
557 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
559 static DEVICE_ATTR_RO(vendor);
561 static ssize_t device_show(struct device *dev,
562 struct device_attribute *dev_attr,
565 struct hv_device *hv_dev = device_to_hv_device(dev);
567 return sprintf(buf, "0x%x\n", hv_dev->device_id);
569 static DEVICE_ATTR_RO(device);
571 static ssize_t driver_override_store(struct device *dev,
572 struct device_attribute *attr,
573 const char *buf, size_t count)
575 struct hv_device *hv_dev = device_to_hv_device(dev);
576 char *driver_override, *old, *cp;
578 /* We need to keep extra room for a newline */
579 if (count >= (PAGE_SIZE - 1))
582 driver_override = kstrndup(buf, count, GFP_KERNEL);
583 if (!driver_override)
586 cp = strchr(driver_override, '\n');
591 old = hv_dev->driver_override;
592 if (strlen(driver_override)) {
593 hv_dev->driver_override = driver_override;
595 kfree(driver_override);
596 hv_dev->driver_override = NULL;
605 static ssize_t driver_override_show(struct device *dev,
606 struct device_attribute *attr, char *buf)
608 struct hv_device *hv_dev = device_to_hv_device(dev);
612 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
617 static DEVICE_ATTR_RW(driver_override);
619 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
620 static struct attribute *vmbus_dev_attrs[] = {
622 &dev_attr_state.attr,
623 &dev_attr_monitor_id.attr,
624 &dev_attr_class_id.attr,
625 &dev_attr_device_id.attr,
626 &dev_attr_modalias.attr,
628 &dev_attr_numa_node.attr,
630 &dev_attr_server_monitor_pending.attr,
631 &dev_attr_client_monitor_pending.attr,
632 &dev_attr_server_monitor_latency.attr,
633 &dev_attr_client_monitor_latency.attr,
634 &dev_attr_server_monitor_conn_id.attr,
635 &dev_attr_client_monitor_conn_id.attr,
636 &dev_attr_out_intr_mask.attr,
637 &dev_attr_out_read_index.attr,
638 &dev_attr_out_write_index.attr,
639 &dev_attr_out_read_bytes_avail.attr,
640 &dev_attr_out_write_bytes_avail.attr,
641 &dev_attr_in_intr_mask.attr,
642 &dev_attr_in_read_index.attr,
643 &dev_attr_in_write_index.attr,
644 &dev_attr_in_read_bytes_avail.attr,
645 &dev_attr_in_write_bytes_avail.attr,
646 &dev_attr_channel_vp_mapping.attr,
647 &dev_attr_vendor.attr,
648 &dev_attr_device.attr,
649 &dev_attr_driver_override.attr,
654 * Device-level attribute_group callback function. Returns the permission for
655 * each attribute, and returns 0 if an attribute is not visible.
657 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
658 struct attribute *attr, int idx)
660 struct device *dev = kobj_to_dev(kobj);
661 const struct hv_device *hv_dev = device_to_hv_device(dev);
663 /* Hide the monitor attributes if the monitor mechanism is not used. */
664 if (!hv_dev->channel->offermsg.monitor_allocated &&
665 (attr == &dev_attr_monitor_id.attr ||
666 attr == &dev_attr_server_monitor_pending.attr ||
667 attr == &dev_attr_client_monitor_pending.attr ||
668 attr == &dev_attr_server_monitor_latency.attr ||
669 attr == &dev_attr_client_monitor_latency.attr ||
670 attr == &dev_attr_server_monitor_conn_id.attr ||
671 attr == &dev_attr_client_monitor_conn_id.attr))
677 static const struct attribute_group vmbus_dev_group = {
678 .attrs = vmbus_dev_attrs,
679 .is_visible = vmbus_dev_attr_is_visible
681 __ATTRIBUTE_GROUPS(vmbus_dev);
683 /* Set up the attribute for /sys/bus/vmbus/hibernation */
684 static ssize_t hibernation_show(struct bus_type *bus, char *buf)
686 return sprintf(buf, "%d\n", !!hv_is_hibernation_supported());
689 static BUS_ATTR_RO(hibernation);
691 static struct attribute *vmbus_bus_attrs[] = {
692 &bus_attr_hibernation.attr,
695 static const struct attribute_group vmbus_bus_group = {
696 .attrs = vmbus_bus_attrs,
698 __ATTRIBUTE_GROUPS(vmbus_bus);
701 * vmbus_uevent - add uevent for our device
703 * This routine is invoked when a device is added or removed on the vmbus to
704 * generate a uevent to udev in the userspace. The udev will then look at its
705 * rule and the uevent generated here to load the appropriate driver
707 * The alias string will be of the form vmbus:guid where guid is the string
708 * representation of the device guid (each byte of the guid will be
709 * represented with two hex characters.
711 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
713 struct hv_device *dev = device_to_hv_device(device);
714 const char *format = "MODALIAS=vmbus:%*phN";
716 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
719 static const struct hv_vmbus_device_id *
720 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
723 return NULL; /* empty device table */
725 for (; !guid_is_null(&id->guid); id++)
726 if (guid_equal(&id->guid, guid))
732 static const struct hv_vmbus_device_id *
733 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
735 const struct hv_vmbus_device_id *id = NULL;
736 struct vmbus_dynid *dynid;
738 spin_lock(&drv->dynids.lock);
739 list_for_each_entry(dynid, &drv->dynids.list, node) {
740 if (guid_equal(&dynid->id.guid, guid)) {
745 spin_unlock(&drv->dynids.lock);
750 static const struct hv_vmbus_device_id vmbus_device_null;
753 * Return a matching hv_vmbus_device_id pointer.
754 * If there is no match, return NULL.
756 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
757 struct hv_device *dev)
759 const guid_t *guid = &dev->dev_type;
760 const struct hv_vmbus_device_id *id;
762 /* When driver_override is set, only bind to the matching driver */
763 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
766 /* Look at the dynamic ids first, before the static ones */
767 id = hv_vmbus_dynid_match(drv, guid);
769 id = hv_vmbus_dev_match(drv->id_table, guid);
771 /* driver_override will always match, send a dummy id */
772 if (!id && dev->driver_override)
773 id = &vmbus_device_null;
778 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
779 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
781 struct vmbus_dynid *dynid;
783 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
787 dynid->id.guid = *guid;
789 spin_lock(&drv->dynids.lock);
790 list_add_tail(&dynid->node, &drv->dynids.list);
791 spin_unlock(&drv->dynids.lock);
793 return driver_attach(&drv->driver);
796 static void vmbus_free_dynids(struct hv_driver *drv)
798 struct vmbus_dynid *dynid, *n;
800 spin_lock(&drv->dynids.lock);
801 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
802 list_del(&dynid->node);
805 spin_unlock(&drv->dynids.lock);
809 * store_new_id - sysfs frontend to vmbus_add_dynid()
811 * Allow GUIDs to be added to an existing driver via sysfs.
813 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
816 struct hv_driver *drv = drv_to_hv_drv(driver);
820 retval = guid_parse(buf, &guid);
824 if (hv_vmbus_dynid_match(drv, &guid))
827 retval = vmbus_add_dynid(drv, &guid);
832 static DRIVER_ATTR_WO(new_id);
835 * store_remove_id - remove a PCI device ID from this driver
837 * Removes a dynamic pci device ID to this driver.
839 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
842 struct hv_driver *drv = drv_to_hv_drv(driver);
843 struct vmbus_dynid *dynid, *n;
847 retval = guid_parse(buf, &guid);
852 spin_lock(&drv->dynids.lock);
853 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
854 struct hv_vmbus_device_id *id = &dynid->id;
856 if (guid_equal(&id->guid, &guid)) {
857 list_del(&dynid->node);
863 spin_unlock(&drv->dynids.lock);
867 static DRIVER_ATTR_WO(remove_id);
869 static struct attribute *vmbus_drv_attrs[] = {
870 &driver_attr_new_id.attr,
871 &driver_attr_remove_id.attr,
874 ATTRIBUTE_GROUPS(vmbus_drv);
878 * vmbus_match - Attempt to match the specified device to the specified driver
880 static int vmbus_match(struct device *device, struct device_driver *driver)
882 struct hv_driver *drv = drv_to_hv_drv(driver);
883 struct hv_device *hv_dev = device_to_hv_device(device);
885 /* The hv_sock driver handles all hv_sock offers. */
886 if (is_hvsock_channel(hv_dev->channel))
889 if (hv_vmbus_get_id(drv, hv_dev))
896 * vmbus_probe - Add the new vmbus's child device
898 static int vmbus_probe(struct device *child_device)
901 struct hv_driver *drv =
902 drv_to_hv_drv(child_device->driver);
903 struct hv_device *dev = device_to_hv_device(child_device);
904 const struct hv_vmbus_device_id *dev_id;
906 dev_id = hv_vmbus_get_id(drv, dev);
908 ret = drv->probe(dev, dev_id);
910 pr_err("probe failed for device %s (%d)\n",
911 dev_name(child_device), ret);
914 pr_err("probe not set for driver %s\n",
915 dev_name(child_device));
922 * vmbus_remove - Remove a vmbus device
924 static int vmbus_remove(struct device *child_device)
926 struct hv_driver *drv;
927 struct hv_device *dev = device_to_hv_device(child_device);
929 if (child_device->driver) {
930 drv = drv_to_hv_drv(child_device->driver);
940 * vmbus_shutdown - Shutdown a vmbus device
942 static void vmbus_shutdown(struct device *child_device)
944 struct hv_driver *drv;
945 struct hv_device *dev = device_to_hv_device(child_device);
948 /* The device may not be attached yet */
949 if (!child_device->driver)
952 drv = drv_to_hv_drv(child_device->driver);
958 #ifdef CONFIG_PM_SLEEP
960 * vmbus_suspend - Suspend a vmbus device
962 static int vmbus_suspend(struct device *child_device)
964 struct hv_driver *drv;
965 struct hv_device *dev = device_to_hv_device(child_device);
967 /* The device may not be attached yet */
968 if (!child_device->driver)
971 drv = drv_to_hv_drv(child_device->driver);
975 return drv->suspend(dev);
979 * vmbus_resume - Resume a vmbus device
981 static int vmbus_resume(struct device *child_device)
983 struct hv_driver *drv;
984 struct hv_device *dev = device_to_hv_device(child_device);
986 /* The device may not be attached yet */
987 if (!child_device->driver)
990 drv = drv_to_hv_drv(child_device->driver);
994 return drv->resume(dev);
997 #define vmbus_suspend NULL
998 #define vmbus_resume NULL
999 #endif /* CONFIG_PM_SLEEP */
1002 * vmbus_device_release - Final callback release of the vmbus child device
1004 static void vmbus_device_release(struct device *device)
1006 struct hv_device *hv_dev = device_to_hv_device(device);
1007 struct vmbus_channel *channel = hv_dev->channel;
1009 hv_debug_rm_dev_dir(hv_dev);
1011 mutex_lock(&vmbus_connection.channel_mutex);
1012 hv_process_channel_removal(channel);
1013 mutex_unlock(&vmbus_connection.channel_mutex);
1018 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
1020 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
1021 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
1022 * is no way to wake up a Generation-2 VM.
1024 * The other 4 ops are for hibernation.
1027 static const struct dev_pm_ops vmbus_pm = {
1028 .suspend_noirq = NULL,
1029 .resume_noirq = NULL,
1030 .freeze_noirq = vmbus_suspend,
1031 .thaw_noirq = vmbus_resume,
1032 .poweroff_noirq = vmbus_suspend,
1033 .restore_noirq = vmbus_resume,
1036 /* The one and only one */
1037 static struct bus_type hv_bus = {
1039 .match = vmbus_match,
1040 .shutdown = vmbus_shutdown,
1041 .remove = vmbus_remove,
1042 .probe = vmbus_probe,
1043 .uevent = vmbus_uevent,
1044 .dev_groups = vmbus_dev_groups,
1045 .drv_groups = vmbus_drv_groups,
1046 .bus_groups = vmbus_bus_groups,
1050 struct onmessage_work_context {
1051 struct work_struct work;
1053 struct hv_message_header header;
1058 static void vmbus_onmessage_work(struct work_struct *work)
1060 struct onmessage_work_context *ctx;
1062 /* Do not process messages if we're in DISCONNECTED state */
1063 if (vmbus_connection.conn_state == DISCONNECTED)
1066 ctx = container_of(work, struct onmessage_work_context,
1068 vmbus_onmessage((struct vmbus_channel_message_header *)
1073 void vmbus_on_msg_dpc(unsigned long data)
1075 struct hv_per_cpu_context *hv_cpu = (void *)data;
1076 void *page_addr = hv_cpu->synic_message_page;
1077 struct hv_message msg_copy, *msg = (struct hv_message *)page_addr +
1079 struct vmbus_channel_message_header *hdr;
1080 enum vmbus_channel_message_type msgtype;
1081 const struct vmbus_channel_message_table_entry *entry;
1082 struct onmessage_work_context *ctx;
1087 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1088 * it is being used in 'struct vmbus_channel_message_header' definition
1089 * which is supposed to match hypervisor ABI.
1091 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1094 * Since the message is in memory shared with the host, an erroneous or
1095 * malicious Hyper-V could modify the message while vmbus_on_msg_dpc()
1096 * or individual message handlers are executing; to prevent this, copy
1097 * the message into private memory.
1099 memcpy(&msg_copy, msg, sizeof(struct hv_message));
1101 message_type = msg_copy.header.message_type;
1102 if (message_type == HVMSG_NONE)
1106 hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload;
1107 msgtype = hdr->msgtype;
1109 trace_vmbus_on_msg_dpc(hdr);
1111 if (msgtype >= CHANNELMSG_COUNT) {
1112 WARN_ONCE(1, "unknown msgtype=%d\n", msgtype);
1116 payload_size = msg_copy.header.payload_size;
1117 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1118 WARN_ONCE(1, "payload size is too large (%d)\n", payload_size);
1122 entry = &channel_message_table[msgtype];
1124 if (!entry->message_handler)
1127 if (payload_size < entry->min_payload_len) {
1128 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size);
1132 if (entry->handler_type == VMHT_BLOCKING) {
1133 ctx = kmalloc(sizeof(*ctx) + payload_size, GFP_ATOMIC);
1137 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1138 memcpy(&ctx->msg, &msg_copy, sizeof(msg->header) + payload_size);
1141 * The host can generate a rescind message while we
1142 * may still be handling the original offer. We deal with
1143 * this condition by relying on the synchronization provided
1144 * by offer_in_progress and by channel_mutex. See also the
1145 * inline comments in vmbus_onoffer_rescind().
1148 case CHANNELMSG_RESCIND_CHANNELOFFER:
1150 * If we are handling the rescind message;
1151 * schedule the work on the global work queue.
1153 * The OFFER message and the RESCIND message should
1154 * not be handled by the same serialized work queue,
1155 * because the OFFER handler may call vmbus_open(),
1156 * which tries to open the channel by sending an
1157 * OPEN_CHANNEL message to the host and waits for
1158 * the host's response; however, if the host has
1159 * rescinded the channel before it receives the
1160 * OPEN_CHANNEL message, the host just silently
1161 * ignores the OPEN_CHANNEL message; as a result,
1162 * the guest's OFFER handler hangs for ever, if we
1163 * handle the RESCIND message in the same serialized
1164 * work queue: the RESCIND handler can not start to
1165 * run before the OFFER handler finishes.
1167 schedule_work(&ctx->work);
1170 case CHANNELMSG_OFFERCHANNEL:
1172 * The host sends the offer message of a given channel
1173 * before sending the rescind message of the same
1174 * channel. These messages are sent to the guest's
1175 * connect CPU; the guest then starts processing them
1176 * in the tasklet handler on this CPU:
1180 * [vmbus_on_msg_dpc()]
1181 * atomic_inc() // CHANNELMSG_OFFERCHANNEL
1184 * [vmbus_on_msg_dpc()]
1185 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
1187 * We rely on the memory-ordering properties of the
1188 * queue_work() and schedule_work() primitives, which
1189 * guarantee that the atomic increment will be visible
1190 * to the CPUs which will execute the offer & rescind
1191 * works by the time these works will start execution.
1193 atomic_inc(&vmbus_connection.offer_in_progress);
1197 queue_work(vmbus_connection.work_queue, &ctx->work);
1200 entry->message_handler(hdr);
1203 vmbus_signal_eom(msg, message_type);
1206 #ifdef CONFIG_PM_SLEEP
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.
1211 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1213 struct onmessage_work_context *ctx;
1214 struct vmbus_channel_rescind_offer *rescind;
1216 WARN_ON(!is_hvsock_channel(channel));
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.
1222 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1223 GFP_KERNEL | __GFP_NOFAIL);
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.
1229 ctx->msg.header.message_type = 1;
1230 ctx->msg.header.payload_size = sizeof(*rescind);
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;
1237 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1239 queue_work(vmbus_connection.work_queue, &ctx->work);
1241 #endif /* CONFIG_PM_SLEEP */
1244 * Schedule all channels with events pending
1246 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1248 unsigned long *recv_int_page;
1251 if (vmbus_proto_version < VERSION_WIN8) {
1252 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1253 recv_int_page = vmbus_connection.recv_int_page;
1256 * When the host is win8 and beyond, the event page
1257 * can be directly checked to get the id of the channel
1258 * that has the interrupt pending.
1260 void *page_addr = hv_cpu->synic_event_page;
1261 union hv_synic_event_flags *event
1262 = (union hv_synic_event_flags *)page_addr +
1265 maxbits = HV_EVENT_FLAGS_COUNT;
1266 recv_int_page = event->flags;
1269 if (unlikely(!recv_int_page))
1272 for_each_set_bit(relid, recv_int_page, maxbits) {
1273 void (*callback_fn)(void *context);
1274 struct vmbus_channel *channel;
1276 if (!sync_test_and_clear_bit(relid, recv_int_page))
1279 /* Special case - vmbus channel protocol msg */
1284 * Pairs with the kfree_rcu() in vmbus_chan_release().
1285 * Guarantees that the channel data structure doesn't
1286 * get freed while the channel pointer below is being
1291 /* Find channel based on relid */
1292 channel = relid2channel(relid);
1293 if (channel == NULL)
1294 goto sched_unlock_rcu;
1296 if (channel->rescind)
1297 goto sched_unlock_rcu;
1300 * Make sure that the ring buffer data structure doesn't get
1301 * freed while we dereference the ring buffer pointer. Test
1302 * for the channel's onchannel_callback being NULL within a
1303 * sched_lock critical section. See also the inline comments
1304 * in vmbus_reset_channel_cb().
1306 spin_lock(&channel->sched_lock);
1308 callback_fn = channel->onchannel_callback;
1309 if (unlikely(callback_fn == NULL))
1312 trace_vmbus_chan_sched(channel);
1314 ++channel->interrupts;
1316 switch (channel->callback_mode) {
1318 (*callback_fn)(channel->channel_callback_context);
1321 case HV_CALL_BATCHED:
1322 hv_begin_read(&channel->inbound);
1324 case HV_CALL_DIRECT:
1325 tasklet_schedule(&channel->callback_event);
1329 spin_unlock(&channel->sched_lock);
1335 static void vmbus_isr(void)
1337 struct hv_per_cpu_context *hv_cpu
1338 = this_cpu_ptr(hv_context.cpu_context);
1339 void *page_addr = hv_cpu->synic_event_page;
1340 struct hv_message *msg;
1341 union hv_synic_event_flags *event;
1342 bool handled = false;
1344 if (unlikely(page_addr == NULL))
1347 event = (union hv_synic_event_flags *)page_addr +
1350 * Check for events before checking for messages. This is the order
1351 * in which events and messages are checked in Windows guests on
1352 * Hyper-V, and the Windows team suggested we do the same.
1355 if ((vmbus_proto_version == VERSION_WS2008) ||
1356 (vmbus_proto_version == VERSION_WIN7)) {
1358 /* Since we are a child, we only need to check bit 0 */
1359 if (sync_test_and_clear_bit(0, event->flags))
1363 * Our host is win8 or above. The signaling mechanism
1364 * has changed and we can directly look at the event page.
1365 * If bit n is set then we have an interrup on the channel
1372 vmbus_chan_sched(hv_cpu);
1374 page_addr = hv_cpu->synic_message_page;
1375 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1377 /* Check if there are actual msgs to be processed */
1378 if (msg->header.message_type != HVMSG_NONE) {
1379 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1381 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1383 tasklet_schedule(&hv_cpu->msg_dpc);
1386 add_interrupt_randomness(vmbus_interrupt, 0);
1389 static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
1396 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1397 * buffer and call into Hyper-V to transfer the data.
1399 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1400 enum kmsg_dump_reason reason)
1402 struct kmsg_dump_iter iter;
1403 size_t bytes_written;
1405 /* We are only interested in panics. */
1406 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1410 * Write dump contents to the page. No need to synchronize; panic should
1411 * be single-threaded.
1413 kmsg_dump_rewind(&iter);
1414 kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1419 * P3 to contain the physical address of the panic page & P4 to
1420 * contain the size of the panic data in that page. Rest of the
1421 * registers are no-op when the NOTIFY_MSG flag is set.
1423 hv_set_register(HV_REGISTER_CRASH_P0, 0);
1424 hv_set_register(HV_REGISTER_CRASH_P1, 0);
1425 hv_set_register(HV_REGISTER_CRASH_P2, 0);
1426 hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page));
1427 hv_set_register(HV_REGISTER_CRASH_P4, bytes_written);
1430 * Let Hyper-V know there is crash data available along with
1431 * the panic message.
1433 hv_set_register(HV_REGISTER_CRASH_CTL,
1434 (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG));
1437 static struct kmsg_dumper hv_kmsg_dumper = {
1438 .dump = hv_kmsg_dump,
1441 static void hv_kmsg_dump_register(void)
1445 hv_panic_page = hv_alloc_hyperv_zeroed_page();
1446 if (!hv_panic_page) {
1447 pr_err("Hyper-V: panic message page memory allocation failed\n");
1451 ret = kmsg_dump_register(&hv_kmsg_dumper);
1453 pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret);
1454 hv_free_hyperv_page((unsigned long)hv_panic_page);
1455 hv_panic_page = NULL;
1459 static struct ctl_table_header *hv_ctl_table_hdr;
1462 * sysctl option to allow the user to control whether kmsg data should be
1463 * reported to Hyper-V on panic.
1465 static struct ctl_table hv_ctl_table[] = {
1467 .procname = "hyperv_record_panic_msg",
1468 .data = &sysctl_record_panic_msg,
1469 .maxlen = sizeof(int),
1471 .proc_handler = proc_dointvec_minmax,
1472 .extra1 = SYSCTL_ZERO,
1473 .extra2 = SYSCTL_ONE
1478 static struct ctl_table hv_root_table[] = {
1480 .procname = "kernel",
1482 .child = hv_ctl_table
1488 * vmbus_bus_init -Main vmbus driver initialization routine.
1491 * - initialize the vmbus driver context
1492 * - invoke the vmbus hv main init routine
1493 * - retrieve the channel offers
1495 static int vmbus_bus_init(void)
1501 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1505 ret = bus_register(&hv_bus);
1510 * VMbus interrupts are best modeled as per-cpu interrupts. If
1511 * on an architecture with support for per-cpu IRQs (e.g. ARM64),
1512 * allocate a per-cpu IRQ using standard Linux kernel functionality.
1513 * If not on such an architecture (e.g., x86/x64), then rely on
1514 * code in the arch-specific portion of the code tree to connect
1515 * the VMbus interrupt handler.
1518 if (vmbus_irq == -1) {
1519 hv_setup_vmbus_handler(vmbus_isr);
1521 vmbus_evt = alloc_percpu(long);
1522 ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr,
1523 "Hyper-V VMbus", vmbus_evt);
1525 pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d",
1527 free_percpu(vmbus_evt);
1532 ret = hv_synic_alloc();
1537 * Initialize the per-cpu interrupt state and stimer state.
1538 * Then connect to the host.
1540 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1541 hv_synic_init, hv_synic_cleanup);
1544 hyperv_cpuhp_online = ret;
1546 ret = vmbus_connect();
1551 * Only register if the crash MSRs are available
1553 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1554 u64 hyperv_crash_ctl;
1556 * Sysctl registration is not fatal, since by default
1557 * reporting is enabled.
1559 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1560 if (!hv_ctl_table_hdr)
1561 pr_err("Hyper-V: sysctl table register error");
1564 * Register for panic kmsg callback only if the right
1565 * capability is supported by the hypervisor.
1567 hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL);
1568 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
1569 hv_kmsg_dump_register();
1571 register_die_notifier(&hyperv_die_block);
1575 * Always register the panic notifier because we need to unload
1576 * the VMbus channel connection to prevent any VMbus
1577 * activity after the VM panics.
1579 atomic_notifier_chain_register(&panic_notifier_list,
1580 &hyperv_panic_block);
1582 vmbus_request_offers();
1587 cpuhp_remove_state(hyperv_cpuhp_online);
1591 if (vmbus_irq == -1) {
1592 hv_remove_vmbus_handler();
1594 free_percpu_irq(vmbus_irq, vmbus_evt);
1595 free_percpu(vmbus_evt);
1598 bus_unregister(&hv_bus);
1599 unregister_sysctl_table(hv_ctl_table_hdr);
1600 hv_ctl_table_hdr = NULL;
1605 * __vmbus_child_driver_register() - Register a vmbus's driver
1606 * @hv_driver: Pointer to driver structure you want to register
1607 * @owner: owner module of the drv
1608 * @mod_name: module name string
1610 * Registers the given driver with Linux through the 'driver_register()' call
1611 * and sets up the hyper-v vmbus handling for this driver.
1612 * It will return the state of the 'driver_register()' call.
1615 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1619 pr_info("registering driver %s\n", hv_driver->name);
1621 ret = vmbus_exists();
1625 hv_driver->driver.name = hv_driver->name;
1626 hv_driver->driver.owner = owner;
1627 hv_driver->driver.mod_name = mod_name;
1628 hv_driver->driver.bus = &hv_bus;
1630 spin_lock_init(&hv_driver->dynids.lock);
1631 INIT_LIST_HEAD(&hv_driver->dynids.list);
1633 ret = driver_register(&hv_driver->driver);
1637 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1640 * vmbus_driver_unregister() - Unregister a vmbus's driver
1641 * @hv_driver: Pointer to driver structure you want to
1644 * Un-register the given driver that was previous registered with a call to
1645 * vmbus_driver_register()
1647 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1649 pr_info("unregistering driver %s\n", hv_driver->name);
1651 if (!vmbus_exists()) {
1652 driver_unregister(&hv_driver->driver);
1653 vmbus_free_dynids(hv_driver);
1656 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1660 * Called when last reference to channel is gone.
1662 static void vmbus_chan_release(struct kobject *kobj)
1664 struct vmbus_channel *channel
1665 = container_of(kobj, struct vmbus_channel, kobj);
1667 kfree_rcu(channel, rcu);
1670 struct vmbus_chan_attribute {
1671 struct attribute attr;
1672 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1673 ssize_t (*store)(struct vmbus_channel *chan,
1674 const char *buf, size_t count);
1676 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1677 struct vmbus_chan_attribute chan_attr_##_name \
1678 = __ATTR(_name, _mode, _show, _store)
1679 #define VMBUS_CHAN_ATTR_RW(_name) \
1680 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1681 #define VMBUS_CHAN_ATTR_RO(_name) \
1682 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1683 #define VMBUS_CHAN_ATTR_WO(_name) \
1684 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1686 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1687 struct attribute *attr, char *buf)
1689 const struct vmbus_chan_attribute *attribute
1690 = container_of(attr, struct vmbus_chan_attribute, attr);
1691 struct vmbus_channel *chan
1692 = container_of(kobj, struct vmbus_channel, kobj);
1694 if (!attribute->show)
1697 return attribute->show(chan, buf);
1700 static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1701 struct attribute *attr, const char *buf,
1704 const struct vmbus_chan_attribute *attribute
1705 = container_of(attr, struct vmbus_chan_attribute, attr);
1706 struct vmbus_channel *chan
1707 = container_of(kobj, struct vmbus_channel, kobj);
1709 if (!attribute->store)
1712 return attribute->store(chan, buf, count);
1715 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1716 .show = vmbus_chan_attr_show,
1717 .store = vmbus_chan_attr_store,
1720 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1722 struct hv_ring_buffer_info *rbi = &channel->outbound;
1725 mutex_lock(&rbi->ring_buffer_mutex);
1726 if (!rbi->ring_buffer) {
1727 mutex_unlock(&rbi->ring_buffer_mutex);
1731 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1732 mutex_unlock(&rbi->ring_buffer_mutex);
1735 static VMBUS_CHAN_ATTR_RO(out_mask);
1737 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1739 struct hv_ring_buffer_info *rbi = &channel->inbound;
1742 mutex_lock(&rbi->ring_buffer_mutex);
1743 if (!rbi->ring_buffer) {
1744 mutex_unlock(&rbi->ring_buffer_mutex);
1748 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1749 mutex_unlock(&rbi->ring_buffer_mutex);
1752 static VMBUS_CHAN_ATTR_RO(in_mask);
1754 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1756 struct hv_ring_buffer_info *rbi = &channel->inbound;
1759 mutex_lock(&rbi->ring_buffer_mutex);
1760 if (!rbi->ring_buffer) {
1761 mutex_unlock(&rbi->ring_buffer_mutex);
1765 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1766 mutex_unlock(&rbi->ring_buffer_mutex);
1769 static VMBUS_CHAN_ATTR_RO(read_avail);
1771 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1773 struct hv_ring_buffer_info *rbi = &channel->outbound;
1776 mutex_lock(&rbi->ring_buffer_mutex);
1777 if (!rbi->ring_buffer) {
1778 mutex_unlock(&rbi->ring_buffer_mutex);
1782 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1783 mutex_unlock(&rbi->ring_buffer_mutex);
1786 static VMBUS_CHAN_ATTR_RO(write_avail);
1788 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1790 return sprintf(buf, "%u\n", channel->target_cpu);
1792 static ssize_t target_cpu_store(struct vmbus_channel *channel,
1793 const char *buf, size_t count)
1795 u32 target_cpu, origin_cpu;
1796 ssize_t ret = count;
1798 if (vmbus_proto_version < VERSION_WIN10_V4_1)
1801 if (sscanf(buf, "%uu", &target_cpu) != 1)
1804 /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1805 if (target_cpu >= nr_cpumask_bits)
1808 /* No CPUs should come up or down during this. */
1811 if (!cpu_online(target_cpu)) {
1817 * Synchronizes target_cpu_store() and channel closure:
1819 * { Initially: state = CHANNEL_OPENED }
1823 * [target_cpu_store()] [vmbus_disconnect_ring()]
1825 * LOCK channel_mutex LOCK channel_mutex
1826 * LOAD r1 = state LOAD r2 = state
1827 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
1828 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
1829 * [...] SEND CLOSECHANNEL
1830 * UNLOCK channel_mutex UNLOCK channel_mutex
1832 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1833 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1835 * Note. The host processes the channel messages "sequentially", in
1836 * the order in which they are received on a per-partition basis.
1838 mutex_lock(&vmbus_connection.channel_mutex);
1841 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1842 * avoid sending the message and fail here for such channels.
1844 if (channel->state != CHANNEL_OPENED_STATE) {
1846 goto cpu_store_unlock;
1849 origin_cpu = channel->target_cpu;
1850 if (target_cpu == origin_cpu)
1851 goto cpu_store_unlock;
1853 if (vmbus_send_modifychannel(channel,
1854 hv_cpu_number_to_vp_number(target_cpu))) {
1856 goto cpu_store_unlock;
1860 * For version before VERSION_WIN10_V5_3, the following warning holds:
1862 * Warning. At this point, there is *no* guarantee that the host will
1863 * have successfully processed the vmbus_send_modifychannel() request.
1864 * See the header comment of vmbus_send_modifychannel() for more info.
1866 * Lags in the processing of the above vmbus_send_modifychannel() can
1867 * result in missed interrupts if the "old" target CPU is taken offline
1868 * before Hyper-V starts sending interrupts to the "new" target CPU.
1869 * But apart from this offlining scenario, the code tolerates such
1870 * lags. It will function correctly even if a channel interrupt comes
1871 * in on a CPU that is different from the channel target_cpu value.
1874 channel->target_cpu = target_cpu;
1876 /* See init_vp_index(). */
1877 if (hv_is_perf_channel(channel))
1878 hv_update_alloced_cpus(origin_cpu, target_cpu);
1880 /* Currently set only for storvsc channels. */
1881 if (channel->change_target_cpu_callback) {
1882 (*channel->change_target_cpu_callback)(channel,
1883 origin_cpu, target_cpu);
1887 mutex_unlock(&vmbus_connection.channel_mutex);
1891 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1893 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1896 return sprintf(buf, "%d\n",
1897 channel_pending(channel,
1898 vmbus_connection.monitor_pages[1]));
1900 static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL);
1902 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1905 return sprintf(buf, "%d\n",
1906 channel_latency(channel,
1907 vmbus_connection.monitor_pages[1]));
1909 static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL);
1911 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1913 return sprintf(buf, "%llu\n", channel->interrupts);
1915 static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL);
1917 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1919 return sprintf(buf, "%llu\n", channel->sig_events);
1921 static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL);
1923 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1926 return sprintf(buf, "%llu\n",
1927 (unsigned long long)channel->intr_in_full);
1929 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1931 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1934 return sprintf(buf, "%llu\n",
1935 (unsigned long long)channel->intr_out_empty);
1937 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1939 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1942 return sprintf(buf, "%llu\n",
1943 (unsigned long long)channel->out_full_first);
1945 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1947 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1950 return sprintf(buf, "%llu\n",
1951 (unsigned long long)channel->out_full_total);
1953 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1955 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1958 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1960 static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL);
1962 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1965 return sprintf(buf, "%u\n",
1966 channel->offermsg.offer.sub_channel_index);
1968 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1970 static struct attribute *vmbus_chan_attrs[] = {
1971 &chan_attr_out_mask.attr,
1972 &chan_attr_in_mask.attr,
1973 &chan_attr_read_avail.attr,
1974 &chan_attr_write_avail.attr,
1975 &chan_attr_cpu.attr,
1976 &chan_attr_pending.attr,
1977 &chan_attr_latency.attr,
1978 &chan_attr_interrupts.attr,
1979 &chan_attr_events.attr,
1980 &chan_attr_intr_in_full.attr,
1981 &chan_attr_intr_out_empty.attr,
1982 &chan_attr_out_full_first.attr,
1983 &chan_attr_out_full_total.attr,
1984 &chan_attr_monitor_id.attr,
1985 &chan_attr_subchannel_id.attr,
1990 * Channel-level attribute_group callback function. Returns the permission for
1991 * each attribute, and returns 0 if an attribute is not visible.
1993 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1994 struct attribute *attr, int idx)
1996 const struct vmbus_channel *channel =
1997 container_of(kobj, struct vmbus_channel, kobj);
1999 /* Hide the monitor attributes if the monitor mechanism is not used. */
2000 if (!channel->offermsg.monitor_allocated &&
2001 (attr == &chan_attr_pending.attr ||
2002 attr == &chan_attr_latency.attr ||
2003 attr == &chan_attr_monitor_id.attr))
2009 static struct attribute_group vmbus_chan_group = {
2010 .attrs = vmbus_chan_attrs,
2011 .is_visible = vmbus_chan_attr_is_visible
2014 static struct kobj_type vmbus_chan_ktype = {
2015 .sysfs_ops = &vmbus_chan_sysfs_ops,
2016 .release = vmbus_chan_release,
2020 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
2022 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
2024 const struct device *device = &dev->device;
2025 struct kobject *kobj = &channel->kobj;
2026 u32 relid = channel->offermsg.child_relid;
2029 kobj->kset = dev->channels_kset;
2030 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
2035 ret = sysfs_create_group(kobj, &vmbus_chan_group);
2039 * The calling functions' error handling paths will cleanup the
2040 * empty channel directory.
2042 dev_err(device, "Unable to set up channel sysfs files\n");
2046 kobject_uevent(kobj, KOBJ_ADD);
2052 * vmbus_remove_channel_attr_group - remove the channel's attribute group
2054 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
2056 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
2060 * vmbus_device_create - Creates and registers a new child device
2063 struct hv_device *vmbus_device_create(const guid_t *type,
2064 const guid_t *instance,
2065 struct vmbus_channel *channel)
2067 struct hv_device *child_device_obj;
2069 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
2070 if (!child_device_obj) {
2071 pr_err("Unable to allocate device object for child device\n");
2075 child_device_obj->channel = channel;
2076 guid_copy(&child_device_obj->dev_type, type);
2077 guid_copy(&child_device_obj->dev_instance, instance);
2078 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
2080 return child_device_obj;
2084 * vmbus_device_register - Register the child device
2086 int vmbus_device_register(struct hv_device *child_device_obj)
2088 struct kobject *kobj = &child_device_obj->device.kobj;
2091 dev_set_name(&child_device_obj->device, "%pUl",
2092 &child_device_obj->channel->offermsg.offer.if_instance);
2094 child_device_obj->device.bus = &hv_bus;
2095 child_device_obj->device.parent = &hv_acpi_dev->dev;
2096 child_device_obj->device.release = vmbus_device_release;
2099 * Register with the LDM. This will kick off the driver/device
2100 * binding...which will eventually call vmbus_match() and vmbus_probe()
2102 ret = device_register(&child_device_obj->device);
2104 pr_err("Unable to register child device\n");
2108 child_device_obj->channels_kset = kset_create_and_add("channels",
2110 if (!child_device_obj->channels_kset) {
2112 goto err_dev_unregister;
2115 ret = vmbus_add_channel_kobj(child_device_obj,
2116 child_device_obj->channel);
2118 pr_err("Unable to register primary channeln");
2119 goto err_kset_unregister;
2121 hv_debug_add_dev_dir(child_device_obj);
2125 err_kset_unregister:
2126 kset_unregister(child_device_obj->channels_kset);
2129 device_unregister(&child_device_obj->device);
2134 * vmbus_device_unregister - Remove the specified child device
2137 void vmbus_device_unregister(struct hv_device *device_obj)
2139 pr_debug("child device %s unregistered\n",
2140 dev_name(&device_obj->device));
2142 kset_unregister(device_obj->channels_kset);
2145 * Kick off the process of unregistering the device.
2146 * This will call vmbus_remove() and eventually vmbus_device_release()
2148 device_unregister(&device_obj->device);
2153 * VMBUS is an acpi enumerated device. Get the information we
2156 #define VTPM_BASE_ADDRESS 0xfed40000
2157 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2159 resource_size_t start = 0;
2160 resource_size_t end = 0;
2161 struct resource *new_res;
2162 struct resource **old_res = &hyperv_mmio;
2163 struct resource **prev_res = NULL;
2166 switch (res->type) {
2169 * "Address" descriptors are for bus windows. Ignore
2170 * "memory" descriptors, which are for registers on
2173 case ACPI_RESOURCE_TYPE_ADDRESS32:
2174 start = res->data.address32.address.minimum;
2175 end = res->data.address32.address.maximum;
2178 case ACPI_RESOURCE_TYPE_ADDRESS64:
2179 start = res->data.address64.address.minimum;
2180 end = res->data.address64.address.maximum;
2184 * The IRQ information is needed only on ARM64, which Hyper-V
2185 * sets up in the extended format. IRQ information is present
2186 * on x86/x64 in the non-extended format but it is not used by
2187 * Linux. So don't bother checking for the non-extended format.
2189 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
2190 if (!acpi_dev_resource_interrupt(res, 0, &r)) {
2191 pr_err("Unable to parse Hyper-V ACPI interrupt\n");
2194 /* ARM64 INTID for VMbus */
2195 vmbus_interrupt = res->data.extended_irq.interrupts[0];
2196 /* Linux IRQ number */
2197 vmbus_irq = r.start;
2201 /* Unused resource type */
2206 * Ignore ranges that are below 1MB, as they're not
2207 * necessary or useful here.
2212 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2214 return AE_NO_MEMORY;
2216 /* If this range overlaps the virtual TPM, truncate it. */
2217 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2218 end = VTPM_BASE_ADDRESS;
2220 new_res->name = "hyperv mmio";
2221 new_res->flags = IORESOURCE_MEM;
2222 new_res->start = start;
2226 * If two ranges are adjacent, merge them.
2234 if (((*old_res)->end + 1) == new_res->start) {
2235 (*old_res)->end = new_res->end;
2240 if ((*old_res)->start == new_res->end + 1) {
2241 (*old_res)->start = new_res->start;
2246 if ((*old_res)->start > new_res->end) {
2247 new_res->sibling = *old_res;
2249 (*prev_res)->sibling = new_res;
2255 old_res = &(*old_res)->sibling;
2262 static int vmbus_acpi_remove(struct acpi_device *device)
2264 struct resource *cur_res;
2265 struct resource *next_res;
2269 __release_region(hyperv_mmio, fb_mmio->start,
2270 resource_size(fb_mmio));
2274 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2275 next_res = cur_res->sibling;
2283 static void vmbus_reserve_fb(void)
2287 * Make a claim for the frame buffer in the resource tree under the
2288 * first node, which will be the one below 4GB. The length seems to
2289 * be underreported, particularly in a Generation 1 VM. So start out
2290 * reserving a larger area and make it smaller until it succeeds.
2293 if (screen_info.lfb_base) {
2294 if (efi_enabled(EFI_BOOT))
2295 size = max_t(__u32, screen_info.lfb_size, 0x800000);
2297 size = max_t(__u32, screen_info.lfb_size, 0x4000000);
2299 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
2300 fb_mmio = __request_region(hyperv_mmio,
2301 screen_info.lfb_base, size,
2308 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2309 * @new: If successful, supplied a pointer to the
2310 * allocated MMIO space.
2311 * @device_obj: Identifies the caller
2312 * @min: Minimum guest physical address of the
2314 * @max: Maximum guest physical address
2315 * @size: Size of the range to be allocated
2316 * @align: Alignment of the range to be allocated
2317 * @fb_overlap_ok: Whether this allocation can be allowed
2318 * to overlap the video frame buffer.
2320 * This function walks the resources granted to VMBus by the
2321 * _CRS object in the ACPI namespace underneath the parent
2322 * "bridge" whether that's a root PCI bus in the Generation 1
2323 * case or a Module Device in the Generation 2 case. It then
2324 * attempts to allocate from the global MMIO pool in a way that
2325 * matches the constraints supplied in these parameters and by
2328 * Return: 0 on success, -errno on failure
2330 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2331 resource_size_t min, resource_size_t max,
2332 resource_size_t size, resource_size_t align,
2335 struct resource *iter, *shadow;
2336 resource_size_t range_min, range_max, start;
2337 const char *dev_n = dev_name(&device_obj->device);
2341 mutex_lock(&hyperv_mmio_lock);
2344 * If overlaps with frame buffers are allowed, then first attempt to
2345 * make the allocation from within the reserved region. Because it
2346 * is already reserved, no shadow allocation is necessary.
2348 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2349 !(max < fb_mmio->start)) {
2351 range_min = fb_mmio->start;
2352 range_max = fb_mmio->end;
2353 start = (range_min + align - 1) & ~(align - 1);
2354 for (; start + size - 1 <= range_max; start += align) {
2355 *new = request_mem_region_exclusive(start, size, dev_n);
2363 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2364 if ((iter->start >= max) || (iter->end <= min))
2367 range_min = iter->start;
2368 range_max = iter->end;
2369 start = (range_min + align - 1) & ~(align - 1);
2370 for (; start + size - 1 <= range_max; start += align) {
2371 shadow = __request_region(iter, start, size, NULL,
2376 *new = request_mem_region_exclusive(start, size, dev_n);
2378 shadow->name = (char *)*new;
2383 __release_region(iter, start, size);
2388 mutex_unlock(&hyperv_mmio_lock);
2391 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2394 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2395 * @start: Base address of region to release.
2396 * @size: Size of the range to be allocated
2398 * This function releases anything requested by
2399 * vmbus_mmio_allocate().
2401 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2403 struct resource *iter;
2405 mutex_lock(&hyperv_mmio_lock);
2406 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2407 if ((iter->start >= start + size) || (iter->end <= start))
2410 __release_region(iter, start, size);
2412 release_mem_region(start, size);
2413 mutex_unlock(&hyperv_mmio_lock);
2416 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2418 static int vmbus_acpi_add(struct acpi_device *device)
2421 int ret_val = -ENODEV;
2422 struct acpi_device *ancestor;
2424 hv_acpi_dev = device;
2426 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2427 vmbus_walk_resources, NULL);
2429 if (ACPI_FAILURE(result))
2432 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2433 * firmware) is the VMOD that has the mmio ranges. Get that.
2435 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2436 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2437 vmbus_walk_resources, NULL);
2439 if (ACPI_FAILURE(result))
2449 complete(&probe_event);
2451 vmbus_acpi_remove(device);
2455 #ifdef CONFIG_PM_SLEEP
2456 static int vmbus_bus_suspend(struct device *dev)
2458 struct vmbus_channel *channel, *sc;
2460 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2462 * We wait here until the completion of any channel
2463 * offers that are currently in progress.
2465 usleep_range(1000, 2000);
2468 mutex_lock(&vmbus_connection.channel_mutex);
2469 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2470 if (!is_hvsock_channel(channel))
2473 vmbus_force_channel_rescinded(channel);
2475 mutex_unlock(&vmbus_connection.channel_mutex);
2478 * Wait until all the sub-channels and hv_sock channels have been
2479 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2480 * they would conflict with the new sub-channels that will be created
2481 * in the resume path. hv_sock channels should also be destroyed, but
2482 * a hv_sock channel of an established hv_sock connection can not be
2483 * really destroyed since it may still be referenced by the userspace
2484 * application, so we just force the hv_sock channel to be rescinded
2485 * by vmbus_force_channel_rescinded(), and the userspace application
2486 * will thoroughly destroy the channel after hibernation.
2488 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2489 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2491 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2492 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2494 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
2495 pr_err("Can not suspend due to a previous failed resuming\n");
2499 mutex_lock(&vmbus_connection.channel_mutex);
2501 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2503 * Remove the channel from the array of channels and invalidate
2504 * the channel's relid. Upon resume, vmbus_onoffer() will fix
2505 * up the relid (and other fields, if necessary) and add the
2506 * channel back to the array.
2508 vmbus_channel_unmap_relid(channel);
2509 channel->offermsg.child_relid = INVALID_RELID;
2511 if (is_hvsock_channel(channel)) {
2512 if (!channel->rescind) {
2513 pr_err("hv_sock channel not rescinded!\n");
2519 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2520 pr_err("Sub-channel not deleted!\n");
2524 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2527 mutex_unlock(&vmbus_connection.channel_mutex);
2529 vmbus_initiate_unload(false);
2531 /* Reset the event for the next resume. */
2532 reinit_completion(&vmbus_connection.ready_for_resume_event);
2537 static int vmbus_bus_resume(struct device *dev)
2539 struct vmbus_channel_msginfo *msginfo;
2544 * We only use the 'vmbus_proto_version', which was in use before
2545 * hibernation, to re-negotiate with the host.
2547 if (!vmbus_proto_version) {
2548 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2552 msgsize = sizeof(*msginfo) +
2553 sizeof(struct vmbus_channel_initiate_contact);
2555 msginfo = kzalloc(msgsize, GFP_KERNEL);
2557 if (msginfo == NULL)
2560 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2567 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2569 vmbus_request_offers();
2571 if (wait_for_completion_timeout(
2572 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
2573 pr_err("Some vmbus device is missing after suspending?\n");
2575 /* Reset the event for the next suspend. */
2576 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2581 #define vmbus_bus_suspend NULL
2582 #define vmbus_bus_resume NULL
2583 #endif /* CONFIG_PM_SLEEP */
2585 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2590 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2593 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2594 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2595 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2596 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2597 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2598 * resume callback must also run via the "noirq" ops.
2600 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2601 * earlier in this file before vmbus_pm.
2604 static const struct dev_pm_ops vmbus_bus_pm = {
2605 .suspend_noirq = NULL,
2606 .resume_noirq = NULL,
2607 .freeze_noirq = vmbus_bus_suspend,
2608 .thaw_noirq = vmbus_bus_resume,
2609 .poweroff_noirq = vmbus_bus_suspend,
2610 .restore_noirq = vmbus_bus_resume
2613 static struct acpi_driver vmbus_acpi_driver = {
2615 .ids = vmbus_acpi_device_ids,
2617 .add = vmbus_acpi_add,
2618 .remove = vmbus_acpi_remove,
2620 .drv.pm = &vmbus_bus_pm,
2623 static void hv_kexec_handler(void)
2625 hv_stimer_global_cleanup();
2626 vmbus_initiate_unload(false);
2627 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2629 cpuhp_remove_state(hyperv_cpuhp_online);
2632 static void hv_crash_handler(struct pt_regs *regs)
2636 vmbus_initiate_unload(true);
2638 * In crash handler we can't schedule synic cleanup for all CPUs,
2639 * doing the cleanup for current CPU only. This should be sufficient
2642 cpu = smp_processor_id();
2643 hv_stimer_cleanup(cpu);
2644 hv_synic_disable_regs(cpu);
2647 static int hv_synic_suspend(void)
2650 * When we reach here, all the non-boot CPUs have been offlined.
2651 * If we're in a legacy configuration where stimer Direct Mode is
2652 * not enabled, the stimers on the non-boot CPUs have been unbound
2653 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2654 * hv_stimer_cleanup() -> clockevents_unbind_device().
2656 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2657 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2658 * 1) it's unnecessary as interrupts remain disabled between
2659 * syscore_suspend() and syscore_resume(): see create_image() and
2660 * resume_target_kernel()
2661 * 2) the stimer on CPU0 is automatically disabled later by
2662 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2663 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2664 * 3) a warning would be triggered if we call
2665 * clockevents_unbind_device(), which may sleep, in an
2666 * interrupts-disabled context.
2669 hv_synic_disable_regs(0);
2674 static void hv_synic_resume(void)
2676 hv_synic_enable_regs(0);
2679 * Note: we don't need to call hv_stimer_init(0), because the timer
2680 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2681 * automatically re-enabled in timekeeping_resume().
2685 /* The callbacks run only on CPU0, with irqs_disabled. */
2686 static struct syscore_ops hv_synic_syscore_ops = {
2687 .suspend = hv_synic_suspend,
2688 .resume = hv_synic_resume,
2691 static int __init hv_acpi_init(void)
2695 if (!hv_is_hyperv_initialized())
2698 if (hv_root_partition)
2701 init_completion(&probe_event);
2704 * Get ACPI resources first.
2706 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2711 t = wait_for_completion_timeout(&probe_event, 5*HZ);
2718 * If we're on an architecture with a hardcoded hypervisor
2719 * vector (i.e. x86/x64), override the VMbus interrupt found
2720 * in the ACPI tables. Ensure vmbus_irq is not set since the
2721 * normal Linux IRQ mechanism is not used in this case.
2723 #ifdef HYPERVISOR_CALLBACK_VECTOR
2724 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR;
2730 ret = vmbus_bus_init();
2734 hv_setup_kexec_handler(hv_kexec_handler);
2735 hv_setup_crash_handler(hv_crash_handler);
2737 register_syscore_ops(&hv_synic_syscore_ops);
2742 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2747 static void __exit vmbus_exit(void)
2751 unregister_syscore_ops(&hv_synic_syscore_ops);
2753 hv_remove_kexec_handler();
2754 hv_remove_crash_handler();
2755 vmbus_connection.conn_state = DISCONNECTED;
2756 hv_stimer_global_cleanup();
2758 if (vmbus_irq == -1) {
2759 hv_remove_vmbus_handler();
2761 free_percpu_irq(vmbus_irq, vmbus_evt);
2762 free_percpu(vmbus_evt);
2764 for_each_online_cpu(cpu) {
2765 struct hv_per_cpu_context *hv_cpu
2766 = per_cpu_ptr(hv_context.cpu_context, cpu);
2768 tasklet_kill(&hv_cpu->msg_dpc);
2770 hv_debug_rm_all_dir();
2772 vmbus_free_channels();
2773 kfree(vmbus_connection.channels);
2775 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2776 kmsg_dump_unregister(&hv_kmsg_dumper);
2777 unregister_die_notifier(&hyperv_die_block);
2778 atomic_notifier_chain_unregister(&panic_notifier_list,
2779 &hyperv_panic_block);
2782 free_page((unsigned long)hv_panic_page);
2783 unregister_sysctl_table(hv_ctl_table_hdr);
2784 hv_ctl_table_hdr = NULL;
2785 bus_unregister(&hv_bus);
2787 cpuhp_remove_state(hyperv_cpuhp_online);
2789 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2793 MODULE_LICENSE("GPL");
2794 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2796 subsys_initcall(hv_acpi_init);
2797 module_exit(vmbus_exit);