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;
52 * Boolean to control whether to report panic messages over Hyper-V.
54 * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
56 static int sysctl_record_panic_msg = 1;
58 static int hyperv_report_reg(void)
60 return !sysctl_record_panic_msg || !hv_panic_page;
63 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
68 vmbus_initiate_unload(true);
71 * Hyper-V should be notified only once about a panic. If we will be
72 * doing hyperv_report_panic_msg() later with kmsg data, don't do
73 * the notification here.
75 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
76 && hyperv_report_reg()) {
77 regs = current_pt_regs();
78 hyperv_report_panic(regs, val, false);
83 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
86 struct die_args *die = (struct die_args *)args;
87 struct pt_regs *regs = die->regs;
89 /* Don't notify Hyper-V if the die event is other than oops */
94 * Hyper-V should be notified only once about a panic. If we will be
95 * doing hyperv_report_panic_msg() later with kmsg data, don't do
96 * the notification here.
98 if (hyperv_report_reg())
99 hyperv_report_panic(regs, val, true);
103 static struct notifier_block hyperv_die_block = {
104 .notifier_call = hyperv_die_event,
106 static struct notifier_block hyperv_panic_block = {
107 .notifier_call = hyperv_panic_event,
110 static const char *fb_mmio_name = "fb_range";
111 static struct resource *fb_mmio;
112 static struct resource *hyperv_mmio;
113 static DEFINE_MUTEX(hyperv_mmio_lock);
115 static int vmbus_exists(void)
117 if (hv_acpi_dev == NULL)
123 static u8 channel_monitor_group(const struct vmbus_channel *channel)
125 return (u8)channel->offermsg.monitorid / 32;
128 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
130 return (u8)channel->offermsg.monitorid % 32;
133 static u32 channel_pending(const struct vmbus_channel *channel,
134 const struct hv_monitor_page *monitor_page)
136 u8 monitor_group = channel_monitor_group(channel);
138 return monitor_page->trigger_group[monitor_group].pending;
141 static u32 channel_latency(const struct vmbus_channel *channel,
142 const struct hv_monitor_page *monitor_page)
144 u8 monitor_group = channel_monitor_group(channel);
145 u8 monitor_offset = channel_monitor_offset(channel);
147 return monitor_page->latency[monitor_group][monitor_offset];
150 static u32 channel_conn_id(struct vmbus_channel *channel,
151 struct hv_monitor_page *monitor_page)
153 u8 monitor_group = channel_monitor_group(channel);
154 u8 monitor_offset = channel_monitor_offset(channel);
155 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
158 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
161 struct hv_device *hv_dev = device_to_hv_device(dev);
163 if (!hv_dev->channel)
165 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
167 static DEVICE_ATTR_RO(id);
169 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
172 struct hv_device *hv_dev = device_to_hv_device(dev);
174 if (!hv_dev->channel)
176 return sprintf(buf, "%d\n", hv_dev->channel->state);
178 static DEVICE_ATTR_RO(state);
180 static ssize_t monitor_id_show(struct device *dev,
181 struct device_attribute *dev_attr, char *buf)
183 struct hv_device *hv_dev = device_to_hv_device(dev);
185 if (!hv_dev->channel)
187 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
189 static DEVICE_ATTR_RO(monitor_id);
191 static ssize_t class_id_show(struct device *dev,
192 struct device_attribute *dev_attr, char *buf)
194 struct hv_device *hv_dev = device_to_hv_device(dev);
196 if (!hv_dev->channel)
198 return sprintf(buf, "{%pUl}\n",
199 &hv_dev->channel->offermsg.offer.if_type);
201 static DEVICE_ATTR_RO(class_id);
203 static ssize_t device_id_show(struct device *dev,
204 struct device_attribute *dev_attr, char *buf)
206 struct hv_device *hv_dev = device_to_hv_device(dev);
208 if (!hv_dev->channel)
210 return sprintf(buf, "{%pUl}\n",
211 &hv_dev->channel->offermsg.offer.if_instance);
213 static DEVICE_ATTR_RO(device_id);
215 static ssize_t modalias_show(struct device *dev,
216 struct device_attribute *dev_attr, char *buf)
218 struct hv_device *hv_dev = device_to_hv_device(dev);
220 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
222 static DEVICE_ATTR_RO(modalias);
225 static ssize_t numa_node_show(struct device *dev,
226 struct device_attribute *attr, char *buf)
228 struct hv_device *hv_dev = device_to_hv_device(dev);
230 if (!hv_dev->channel)
233 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
235 static DEVICE_ATTR_RO(numa_node);
238 static ssize_t server_monitor_pending_show(struct device *dev,
239 struct device_attribute *dev_attr,
242 struct hv_device *hv_dev = device_to_hv_device(dev);
244 if (!hv_dev->channel)
246 return sprintf(buf, "%d\n",
247 channel_pending(hv_dev->channel,
248 vmbus_connection.monitor_pages[0]));
250 static DEVICE_ATTR_RO(server_monitor_pending);
252 static ssize_t client_monitor_pending_show(struct device *dev,
253 struct device_attribute *dev_attr,
256 struct hv_device *hv_dev = device_to_hv_device(dev);
258 if (!hv_dev->channel)
260 return sprintf(buf, "%d\n",
261 channel_pending(hv_dev->channel,
262 vmbus_connection.monitor_pages[1]));
264 static DEVICE_ATTR_RO(client_monitor_pending);
266 static ssize_t server_monitor_latency_show(struct device *dev,
267 struct device_attribute *dev_attr,
270 struct hv_device *hv_dev = device_to_hv_device(dev);
272 if (!hv_dev->channel)
274 return sprintf(buf, "%d\n",
275 channel_latency(hv_dev->channel,
276 vmbus_connection.monitor_pages[0]));
278 static DEVICE_ATTR_RO(server_monitor_latency);
280 static ssize_t client_monitor_latency_show(struct device *dev,
281 struct device_attribute *dev_attr,
284 struct hv_device *hv_dev = device_to_hv_device(dev);
286 if (!hv_dev->channel)
288 return sprintf(buf, "%d\n",
289 channel_latency(hv_dev->channel,
290 vmbus_connection.monitor_pages[1]));
292 static DEVICE_ATTR_RO(client_monitor_latency);
294 static ssize_t server_monitor_conn_id_show(struct device *dev,
295 struct device_attribute *dev_attr,
298 struct hv_device *hv_dev = device_to_hv_device(dev);
300 if (!hv_dev->channel)
302 return sprintf(buf, "%d\n",
303 channel_conn_id(hv_dev->channel,
304 vmbus_connection.monitor_pages[0]));
306 static DEVICE_ATTR_RO(server_monitor_conn_id);
308 static ssize_t client_monitor_conn_id_show(struct device *dev,
309 struct device_attribute *dev_attr,
312 struct hv_device *hv_dev = device_to_hv_device(dev);
314 if (!hv_dev->channel)
316 return sprintf(buf, "%d\n",
317 channel_conn_id(hv_dev->channel,
318 vmbus_connection.monitor_pages[1]));
320 static DEVICE_ATTR_RO(client_monitor_conn_id);
322 static ssize_t out_intr_mask_show(struct device *dev,
323 struct device_attribute *dev_attr, char *buf)
325 struct hv_device *hv_dev = device_to_hv_device(dev);
326 struct hv_ring_buffer_debug_info outbound;
329 if (!hv_dev->channel)
332 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
337 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
339 static DEVICE_ATTR_RO(out_intr_mask);
341 static ssize_t out_read_index_show(struct device *dev,
342 struct device_attribute *dev_attr, char *buf)
344 struct hv_device *hv_dev = device_to_hv_device(dev);
345 struct hv_ring_buffer_debug_info outbound;
348 if (!hv_dev->channel)
351 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
355 return sprintf(buf, "%d\n", outbound.current_read_index);
357 static DEVICE_ATTR_RO(out_read_index);
359 static ssize_t out_write_index_show(struct device *dev,
360 struct device_attribute *dev_attr,
363 struct hv_device *hv_dev = device_to_hv_device(dev);
364 struct hv_ring_buffer_debug_info outbound;
367 if (!hv_dev->channel)
370 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
374 return sprintf(buf, "%d\n", outbound.current_write_index);
376 static DEVICE_ATTR_RO(out_write_index);
378 static ssize_t out_read_bytes_avail_show(struct device *dev,
379 struct device_attribute *dev_attr,
382 struct hv_device *hv_dev = device_to_hv_device(dev);
383 struct hv_ring_buffer_debug_info outbound;
386 if (!hv_dev->channel)
389 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
393 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
395 static DEVICE_ATTR_RO(out_read_bytes_avail);
397 static ssize_t out_write_bytes_avail_show(struct device *dev,
398 struct device_attribute *dev_attr,
401 struct hv_device *hv_dev = device_to_hv_device(dev);
402 struct hv_ring_buffer_debug_info outbound;
405 if (!hv_dev->channel)
408 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
412 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
414 static DEVICE_ATTR_RO(out_write_bytes_avail);
416 static ssize_t in_intr_mask_show(struct device *dev,
417 struct device_attribute *dev_attr, char *buf)
419 struct hv_device *hv_dev = device_to_hv_device(dev);
420 struct hv_ring_buffer_debug_info inbound;
423 if (!hv_dev->channel)
426 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
430 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
432 static DEVICE_ATTR_RO(in_intr_mask);
434 static ssize_t in_read_index_show(struct device *dev,
435 struct device_attribute *dev_attr, char *buf)
437 struct hv_device *hv_dev = device_to_hv_device(dev);
438 struct hv_ring_buffer_debug_info inbound;
441 if (!hv_dev->channel)
444 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
448 return sprintf(buf, "%d\n", inbound.current_read_index);
450 static DEVICE_ATTR_RO(in_read_index);
452 static ssize_t in_write_index_show(struct device *dev,
453 struct device_attribute *dev_attr, char *buf)
455 struct hv_device *hv_dev = device_to_hv_device(dev);
456 struct hv_ring_buffer_debug_info inbound;
459 if (!hv_dev->channel)
462 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
466 return sprintf(buf, "%d\n", inbound.current_write_index);
468 static DEVICE_ATTR_RO(in_write_index);
470 static ssize_t in_read_bytes_avail_show(struct device *dev,
471 struct device_attribute *dev_attr,
474 struct hv_device *hv_dev = device_to_hv_device(dev);
475 struct hv_ring_buffer_debug_info inbound;
478 if (!hv_dev->channel)
481 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
485 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
487 static DEVICE_ATTR_RO(in_read_bytes_avail);
489 static ssize_t in_write_bytes_avail_show(struct device *dev,
490 struct device_attribute *dev_attr,
493 struct hv_device *hv_dev = device_to_hv_device(dev);
494 struct hv_ring_buffer_debug_info inbound;
497 if (!hv_dev->channel)
500 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
504 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
506 static DEVICE_ATTR_RO(in_write_bytes_avail);
508 static ssize_t channel_vp_mapping_show(struct device *dev,
509 struct device_attribute *dev_attr,
512 struct hv_device *hv_dev = device_to_hv_device(dev);
513 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
514 int buf_size = PAGE_SIZE, n_written, tot_written;
515 struct list_head *cur;
520 mutex_lock(&vmbus_connection.channel_mutex);
522 tot_written = snprintf(buf, buf_size, "%u:%u\n",
523 channel->offermsg.child_relid, channel->target_cpu);
525 list_for_each(cur, &channel->sc_list) {
526 if (tot_written >= buf_size - 1)
529 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
530 n_written = scnprintf(buf + tot_written,
531 buf_size - tot_written,
533 cur_sc->offermsg.child_relid,
535 tot_written += n_written;
538 mutex_unlock(&vmbus_connection.channel_mutex);
542 static DEVICE_ATTR_RO(channel_vp_mapping);
544 static ssize_t vendor_show(struct device *dev,
545 struct device_attribute *dev_attr,
548 struct hv_device *hv_dev = device_to_hv_device(dev);
549 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
551 static DEVICE_ATTR_RO(vendor);
553 static ssize_t device_show(struct device *dev,
554 struct device_attribute *dev_attr,
557 struct hv_device *hv_dev = device_to_hv_device(dev);
558 return sprintf(buf, "0x%x\n", hv_dev->device_id);
560 static DEVICE_ATTR_RO(device);
562 static ssize_t driver_override_store(struct device *dev,
563 struct device_attribute *attr,
564 const char *buf, size_t count)
566 struct hv_device *hv_dev = device_to_hv_device(dev);
567 char *driver_override, *old, *cp;
569 /* We need to keep extra room for a newline */
570 if (count >= (PAGE_SIZE - 1))
573 driver_override = kstrndup(buf, count, GFP_KERNEL);
574 if (!driver_override)
577 cp = strchr(driver_override, '\n');
582 old = hv_dev->driver_override;
583 if (strlen(driver_override)) {
584 hv_dev->driver_override = driver_override;
586 kfree(driver_override);
587 hv_dev->driver_override = NULL;
596 static ssize_t driver_override_show(struct device *dev,
597 struct device_attribute *attr, char *buf)
599 struct hv_device *hv_dev = device_to_hv_device(dev);
603 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
608 static DEVICE_ATTR_RW(driver_override);
610 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
611 static struct attribute *vmbus_dev_attrs[] = {
613 &dev_attr_state.attr,
614 &dev_attr_monitor_id.attr,
615 &dev_attr_class_id.attr,
616 &dev_attr_device_id.attr,
617 &dev_attr_modalias.attr,
619 &dev_attr_numa_node.attr,
621 &dev_attr_server_monitor_pending.attr,
622 &dev_attr_client_monitor_pending.attr,
623 &dev_attr_server_monitor_latency.attr,
624 &dev_attr_client_monitor_latency.attr,
625 &dev_attr_server_monitor_conn_id.attr,
626 &dev_attr_client_monitor_conn_id.attr,
627 &dev_attr_out_intr_mask.attr,
628 &dev_attr_out_read_index.attr,
629 &dev_attr_out_write_index.attr,
630 &dev_attr_out_read_bytes_avail.attr,
631 &dev_attr_out_write_bytes_avail.attr,
632 &dev_attr_in_intr_mask.attr,
633 &dev_attr_in_read_index.attr,
634 &dev_attr_in_write_index.attr,
635 &dev_attr_in_read_bytes_avail.attr,
636 &dev_attr_in_write_bytes_avail.attr,
637 &dev_attr_channel_vp_mapping.attr,
638 &dev_attr_vendor.attr,
639 &dev_attr_device.attr,
640 &dev_attr_driver_override.attr,
645 * Device-level attribute_group callback function. Returns the permission for
646 * each attribute, and returns 0 if an attribute is not visible.
648 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
649 struct attribute *attr, int idx)
651 struct device *dev = kobj_to_dev(kobj);
652 const struct hv_device *hv_dev = device_to_hv_device(dev);
654 /* Hide the monitor attributes if the monitor mechanism is not used. */
655 if (!hv_dev->channel->offermsg.monitor_allocated &&
656 (attr == &dev_attr_monitor_id.attr ||
657 attr == &dev_attr_server_monitor_pending.attr ||
658 attr == &dev_attr_client_monitor_pending.attr ||
659 attr == &dev_attr_server_monitor_latency.attr ||
660 attr == &dev_attr_client_monitor_latency.attr ||
661 attr == &dev_attr_server_monitor_conn_id.attr ||
662 attr == &dev_attr_client_monitor_conn_id.attr))
668 static const struct attribute_group vmbus_dev_group = {
669 .attrs = vmbus_dev_attrs,
670 .is_visible = vmbus_dev_attr_is_visible
672 __ATTRIBUTE_GROUPS(vmbus_dev);
675 * vmbus_uevent - add uevent for our device
677 * This routine is invoked when a device is added or removed on the vmbus to
678 * generate a uevent to udev in the userspace. The udev will then look at its
679 * rule and the uevent generated here to load the appropriate driver
681 * The alias string will be of the form vmbus:guid where guid is the string
682 * representation of the device guid (each byte of the guid will be
683 * represented with two hex characters.
685 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
687 struct hv_device *dev = device_to_hv_device(device);
688 const char *format = "MODALIAS=vmbus:%*phN";
690 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
693 static const struct hv_vmbus_device_id *
694 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
697 return NULL; /* empty device table */
699 for (; !guid_is_null(&id->guid); id++)
700 if (guid_equal(&id->guid, guid))
706 static const struct hv_vmbus_device_id *
707 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
709 const struct hv_vmbus_device_id *id = NULL;
710 struct vmbus_dynid *dynid;
712 spin_lock(&drv->dynids.lock);
713 list_for_each_entry(dynid, &drv->dynids.list, node) {
714 if (guid_equal(&dynid->id.guid, guid)) {
719 spin_unlock(&drv->dynids.lock);
724 static const struct hv_vmbus_device_id vmbus_device_null;
727 * Return a matching hv_vmbus_device_id pointer.
728 * If there is no match, return NULL.
730 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
731 struct hv_device *dev)
733 const guid_t *guid = &dev->dev_type;
734 const struct hv_vmbus_device_id *id;
736 /* When driver_override is set, only bind to the matching driver */
737 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
740 /* Look at the dynamic ids first, before the static ones */
741 id = hv_vmbus_dynid_match(drv, guid);
743 id = hv_vmbus_dev_match(drv->id_table, guid);
745 /* driver_override will always match, send a dummy id */
746 if (!id && dev->driver_override)
747 id = &vmbus_device_null;
752 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
753 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
755 struct vmbus_dynid *dynid;
757 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
761 dynid->id.guid = *guid;
763 spin_lock(&drv->dynids.lock);
764 list_add_tail(&dynid->node, &drv->dynids.list);
765 spin_unlock(&drv->dynids.lock);
767 return driver_attach(&drv->driver);
770 static void vmbus_free_dynids(struct hv_driver *drv)
772 struct vmbus_dynid *dynid, *n;
774 spin_lock(&drv->dynids.lock);
775 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
776 list_del(&dynid->node);
779 spin_unlock(&drv->dynids.lock);
783 * store_new_id - sysfs frontend to vmbus_add_dynid()
785 * Allow GUIDs to be added to an existing driver via sysfs.
787 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
790 struct hv_driver *drv = drv_to_hv_drv(driver);
794 retval = guid_parse(buf, &guid);
798 if (hv_vmbus_dynid_match(drv, &guid))
801 retval = vmbus_add_dynid(drv, &guid);
806 static DRIVER_ATTR_WO(new_id);
809 * store_remove_id - remove a PCI device ID from this driver
811 * Removes a dynamic pci device ID to this driver.
813 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
816 struct hv_driver *drv = drv_to_hv_drv(driver);
817 struct vmbus_dynid *dynid, *n;
821 retval = guid_parse(buf, &guid);
826 spin_lock(&drv->dynids.lock);
827 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
828 struct hv_vmbus_device_id *id = &dynid->id;
830 if (guid_equal(&id->guid, &guid)) {
831 list_del(&dynid->node);
837 spin_unlock(&drv->dynids.lock);
841 static DRIVER_ATTR_WO(remove_id);
843 static struct attribute *vmbus_drv_attrs[] = {
844 &driver_attr_new_id.attr,
845 &driver_attr_remove_id.attr,
848 ATTRIBUTE_GROUPS(vmbus_drv);
852 * vmbus_match - Attempt to match the specified device to the specified driver
854 static int vmbus_match(struct device *device, struct device_driver *driver)
856 struct hv_driver *drv = drv_to_hv_drv(driver);
857 struct hv_device *hv_dev = device_to_hv_device(device);
859 /* The hv_sock driver handles all hv_sock offers. */
860 if (is_hvsock_channel(hv_dev->channel))
863 if (hv_vmbus_get_id(drv, hv_dev))
870 * vmbus_probe - Add the new vmbus's child device
872 static int vmbus_probe(struct device *child_device)
875 struct hv_driver *drv =
876 drv_to_hv_drv(child_device->driver);
877 struct hv_device *dev = device_to_hv_device(child_device);
878 const struct hv_vmbus_device_id *dev_id;
880 dev_id = hv_vmbus_get_id(drv, dev);
882 ret = drv->probe(dev, dev_id);
884 pr_err("probe failed for device %s (%d)\n",
885 dev_name(child_device), ret);
888 pr_err("probe not set for driver %s\n",
889 dev_name(child_device));
896 * vmbus_remove - Remove a vmbus device
898 static int vmbus_remove(struct device *child_device)
900 struct hv_driver *drv;
901 struct hv_device *dev = device_to_hv_device(child_device);
903 if (child_device->driver) {
904 drv = drv_to_hv_drv(child_device->driver);
914 * vmbus_shutdown - Shutdown a vmbus device
916 static void vmbus_shutdown(struct device *child_device)
918 struct hv_driver *drv;
919 struct hv_device *dev = device_to_hv_device(child_device);
922 /* The device may not be attached yet */
923 if (!child_device->driver)
926 drv = drv_to_hv_drv(child_device->driver);
932 #ifdef CONFIG_PM_SLEEP
934 * vmbus_suspend - Suspend a vmbus device
936 static int vmbus_suspend(struct device *child_device)
938 struct hv_driver *drv;
939 struct hv_device *dev = device_to_hv_device(child_device);
941 /* The device may not be attached yet */
942 if (!child_device->driver)
945 drv = drv_to_hv_drv(child_device->driver);
949 return drv->suspend(dev);
953 * vmbus_resume - Resume a vmbus device
955 static int vmbus_resume(struct device *child_device)
957 struct hv_driver *drv;
958 struct hv_device *dev = device_to_hv_device(child_device);
960 /* The device may not be attached yet */
961 if (!child_device->driver)
964 drv = drv_to_hv_drv(child_device->driver);
968 return drv->resume(dev);
971 #define vmbus_suspend NULL
972 #define vmbus_resume NULL
973 #endif /* CONFIG_PM_SLEEP */
976 * vmbus_device_release - Final callback release of the vmbus child device
978 static void vmbus_device_release(struct device *device)
980 struct hv_device *hv_dev = device_to_hv_device(device);
981 struct vmbus_channel *channel = hv_dev->channel;
983 hv_debug_rm_dev_dir(hv_dev);
985 mutex_lock(&vmbus_connection.channel_mutex);
986 hv_process_channel_removal(channel);
987 mutex_unlock(&vmbus_connection.channel_mutex);
992 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
994 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
995 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
996 * is no way to wake up a Generation-2 VM.
998 * The other 4 ops are for hibernation.
1001 static const struct dev_pm_ops vmbus_pm = {
1002 .suspend_noirq = NULL,
1003 .resume_noirq = NULL,
1004 .freeze_noirq = vmbus_suspend,
1005 .thaw_noirq = vmbus_resume,
1006 .poweroff_noirq = vmbus_suspend,
1007 .restore_noirq = vmbus_resume,
1010 /* The one and only one */
1011 static struct bus_type hv_bus = {
1013 .match = vmbus_match,
1014 .shutdown = vmbus_shutdown,
1015 .remove = vmbus_remove,
1016 .probe = vmbus_probe,
1017 .uevent = vmbus_uevent,
1018 .dev_groups = vmbus_dev_groups,
1019 .drv_groups = vmbus_drv_groups,
1023 struct onmessage_work_context {
1024 struct work_struct work;
1026 struct hv_message_header header;
1031 static void vmbus_onmessage_work(struct work_struct *work)
1033 struct onmessage_work_context *ctx;
1035 /* Do not process messages if we're in DISCONNECTED state */
1036 if (vmbus_connection.conn_state == DISCONNECTED)
1039 ctx = container_of(work, struct onmessage_work_context,
1041 vmbus_onmessage((struct vmbus_channel_message_header *)
1046 void vmbus_on_msg_dpc(unsigned long data)
1048 struct hv_per_cpu_context *hv_cpu = (void *)data;
1049 void *page_addr = hv_cpu->synic_message_page;
1050 struct hv_message *msg = (struct hv_message *)page_addr +
1052 struct vmbus_channel_message_header *hdr;
1053 const struct vmbus_channel_message_table_entry *entry;
1054 struct onmessage_work_context *ctx;
1055 u32 message_type = msg->header.message_type;
1058 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1059 * it is being used in 'struct vmbus_channel_message_header' definition
1060 * which is supposed to match hypervisor ABI.
1062 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1064 if (message_type == HVMSG_NONE)
1068 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1070 trace_vmbus_on_msg_dpc(hdr);
1072 if (hdr->msgtype >= CHANNELMSG_COUNT) {
1073 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1077 if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1078 WARN_ONCE(1, "payload size is too large (%d)\n",
1079 msg->header.payload_size);
1083 entry = &channel_message_table[hdr->msgtype];
1085 if (!entry->message_handler)
1088 if (msg->header.payload_size < entry->min_payload_len) {
1089 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",
1090 hdr->msgtype, msg->header.payload_size);
1094 if (entry->handler_type == VMHT_BLOCKING) {
1095 ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,
1100 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1101 memcpy(&ctx->msg, msg, sizeof(msg->header) +
1102 msg->header.payload_size);
1105 * The host can generate a rescind message while we
1106 * may still be handling the original offer. We deal with
1107 * this condition by relying on the synchronization provided
1108 * by offer_in_progress and by channel_mutex. See also the
1109 * inline comments in vmbus_onoffer_rescind().
1111 switch (hdr->msgtype) {
1112 case CHANNELMSG_RESCIND_CHANNELOFFER:
1114 * If we are handling the rescind message;
1115 * schedule the work on the global work queue.
1117 * The OFFER message and the RESCIND message should
1118 * not be handled by the same serialized work queue,
1119 * because the OFFER handler may call vmbus_open(),
1120 * which tries to open the channel by sending an
1121 * OPEN_CHANNEL message to the host and waits for
1122 * the host's response; however, if the host has
1123 * rescinded the channel before it receives the
1124 * OPEN_CHANNEL message, the host just silently
1125 * ignores the OPEN_CHANNEL message; as a result,
1126 * the guest's OFFER handler hangs for ever, if we
1127 * handle the RESCIND message in the same serialized
1128 * work queue: the RESCIND handler can not start to
1129 * run before the OFFER handler finishes.
1131 schedule_work(&ctx->work);
1134 case CHANNELMSG_OFFERCHANNEL:
1136 * The host sends the offer message of a given channel
1137 * before sending the rescind message of the same
1138 * channel. These messages are sent to the guest's
1139 * connect CPU; the guest then starts processing them
1140 * in the tasklet handler on this CPU:
1144 * [vmbus_on_msg_dpc()]
1145 * atomic_inc() // CHANNELMSG_OFFERCHANNEL
1148 * [vmbus_on_msg_dpc()]
1149 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
1151 * We rely on the memory-ordering properties of the
1152 * queue_work() and schedule_work() primitives, which
1153 * guarantee that the atomic increment will be visible
1154 * to the CPUs which will execute the offer & rescind
1155 * works by the time these works will start execution.
1157 atomic_inc(&vmbus_connection.offer_in_progress);
1161 queue_work(vmbus_connection.work_queue, &ctx->work);
1164 entry->message_handler(hdr);
1167 vmbus_signal_eom(msg, message_type);
1170 #ifdef CONFIG_PM_SLEEP
1172 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1173 * hibernation, because hv_sock connections can not persist across hibernation.
1175 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1177 struct onmessage_work_context *ctx;
1178 struct vmbus_channel_rescind_offer *rescind;
1180 WARN_ON(!is_hvsock_channel(channel));
1183 * Allocation size is small and the allocation should really not fail,
1184 * otherwise the state of the hv_sock connections ends up in limbo.
1186 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1187 GFP_KERNEL | __GFP_NOFAIL);
1190 * So far, these are not really used by Linux. Just set them to the
1191 * reasonable values conforming to the definitions of the fields.
1193 ctx->msg.header.message_type = 1;
1194 ctx->msg.header.payload_size = sizeof(*rescind);
1196 /* These values are actually used by Linux. */
1197 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1198 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1199 rescind->child_relid = channel->offermsg.child_relid;
1201 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1203 queue_work(vmbus_connection.work_queue, &ctx->work);
1205 #endif /* CONFIG_PM_SLEEP */
1208 * Schedule all channels with events pending
1210 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1212 unsigned long *recv_int_page;
1215 if (vmbus_proto_version < VERSION_WIN8) {
1216 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1217 recv_int_page = vmbus_connection.recv_int_page;
1220 * When the host is win8 and beyond, the event page
1221 * can be directly checked to get the id of the channel
1222 * that has the interrupt pending.
1224 void *page_addr = hv_cpu->synic_event_page;
1225 union hv_synic_event_flags *event
1226 = (union hv_synic_event_flags *)page_addr +
1229 maxbits = HV_EVENT_FLAGS_COUNT;
1230 recv_int_page = event->flags;
1233 if (unlikely(!recv_int_page))
1236 for_each_set_bit(relid, recv_int_page, maxbits) {
1237 void (*callback_fn)(void *context);
1238 struct vmbus_channel *channel;
1240 if (!sync_test_and_clear_bit(relid, recv_int_page))
1243 /* Special case - vmbus channel protocol msg */
1248 * Pairs with the kfree_rcu() in vmbus_chan_release().
1249 * Guarantees that the channel data structure doesn't
1250 * get freed while the channel pointer below is being
1255 /* Find channel based on relid */
1256 channel = relid2channel(relid);
1257 if (channel == NULL)
1258 goto sched_unlock_rcu;
1260 if (channel->rescind)
1261 goto sched_unlock_rcu;
1264 * Make sure that the ring buffer data structure doesn't get
1265 * freed while we dereference the ring buffer pointer. Test
1266 * for the channel's onchannel_callback being NULL within a
1267 * sched_lock critical section. See also the inline comments
1268 * in vmbus_reset_channel_cb().
1270 spin_lock(&channel->sched_lock);
1272 callback_fn = channel->onchannel_callback;
1273 if (unlikely(callback_fn == NULL))
1276 trace_vmbus_chan_sched(channel);
1278 ++channel->interrupts;
1280 switch (channel->callback_mode) {
1282 (*callback_fn)(channel->channel_callback_context);
1285 case HV_CALL_BATCHED:
1286 hv_begin_read(&channel->inbound);
1288 case HV_CALL_DIRECT:
1289 tasklet_schedule(&channel->callback_event);
1293 spin_unlock(&channel->sched_lock);
1299 static void vmbus_isr(void)
1301 struct hv_per_cpu_context *hv_cpu
1302 = this_cpu_ptr(hv_context.cpu_context);
1303 void *page_addr = hv_cpu->synic_event_page;
1304 struct hv_message *msg;
1305 union hv_synic_event_flags *event;
1306 bool handled = false;
1308 if (unlikely(page_addr == NULL))
1311 event = (union hv_synic_event_flags *)page_addr +
1314 * Check for events before checking for messages. This is the order
1315 * in which events and messages are checked in Windows guests on
1316 * Hyper-V, and the Windows team suggested we do the same.
1319 if ((vmbus_proto_version == VERSION_WS2008) ||
1320 (vmbus_proto_version == VERSION_WIN7)) {
1322 /* Since we are a child, we only need to check bit 0 */
1323 if (sync_test_and_clear_bit(0, event->flags))
1327 * Our host is win8 or above. The signaling mechanism
1328 * has changed and we can directly look at the event page.
1329 * If bit n is set then we have an interrup on the channel
1336 vmbus_chan_sched(hv_cpu);
1338 page_addr = hv_cpu->synic_message_page;
1339 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1341 /* Check if there are actual msgs to be processed */
1342 if (msg->header.message_type != HVMSG_NONE) {
1343 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1345 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1347 tasklet_schedule(&hv_cpu->msg_dpc);
1350 add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1354 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1355 * buffer and call into Hyper-V to transfer the data.
1357 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1358 enum kmsg_dump_reason reason)
1360 size_t bytes_written;
1361 phys_addr_t panic_pa;
1363 /* We are only interested in panics. */
1364 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1367 panic_pa = virt_to_phys(hv_panic_page);
1370 * Write dump contents to the page. No need to synchronize; panic should
1371 * be single-threaded.
1373 kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1376 hyperv_report_panic_msg(panic_pa, bytes_written);
1379 static struct kmsg_dumper hv_kmsg_dumper = {
1380 .dump = hv_kmsg_dump,
1383 static struct ctl_table_header *hv_ctl_table_hdr;
1386 * sysctl option to allow the user to control whether kmsg data should be
1387 * reported to Hyper-V on panic.
1389 static struct ctl_table hv_ctl_table[] = {
1391 .procname = "hyperv_record_panic_msg",
1392 .data = &sysctl_record_panic_msg,
1393 .maxlen = sizeof(int),
1395 .proc_handler = proc_dointvec_minmax,
1396 .extra1 = SYSCTL_ZERO,
1397 .extra2 = SYSCTL_ONE
1402 static struct ctl_table hv_root_table[] = {
1404 .procname = "kernel",
1406 .child = hv_ctl_table
1412 * vmbus_bus_init -Main vmbus driver initialization routine.
1415 * - initialize the vmbus driver context
1416 * - invoke the vmbus hv main init routine
1417 * - retrieve the channel offers
1419 static int vmbus_bus_init(void)
1425 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1429 ret = bus_register(&hv_bus);
1433 hv_setup_vmbus_irq(vmbus_isr);
1435 ret = hv_synic_alloc();
1440 * Initialize the per-cpu interrupt state and stimer state.
1441 * Then connect to the host.
1443 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1444 hv_synic_init, hv_synic_cleanup);
1447 hyperv_cpuhp_online = ret;
1449 ret = vmbus_connect();
1454 * Only register if the crash MSRs are available
1456 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1457 u64 hyperv_crash_ctl;
1459 * Sysctl registration is not fatal, since by default
1460 * reporting is enabled.
1462 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1463 if (!hv_ctl_table_hdr)
1464 pr_err("Hyper-V: sysctl table register error");
1467 * Register for panic kmsg callback only if the right
1468 * capability is supported by the hypervisor.
1470 hv_get_crash_ctl(hyperv_crash_ctl);
1471 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1472 hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
1473 if (hv_panic_page) {
1474 ret = kmsg_dump_register(&hv_kmsg_dumper);
1476 pr_err("Hyper-V: kmsg dump register "
1477 "error 0x%x\n", ret);
1478 hv_free_hyperv_page(
1479 (unsigned long)hv_panic_page);
1480 hv_panic_page = NULL;
1483 pr_err("Hyper-V: panic message page memory "
1484 "allocation failed");
1487 register_die_notifier(&hyperv_die_block);
1491 * Always register the panic notifier because we need to unload
1492 * the VMbus channel connection to prevent any VMbus
1493 * activity after the VM panics.
1495 atomic_notifier_chain_register(&panic_notifier_list,
1496 &hyperv_panic_block);
1498 vmbus_request_offers();
1503 cpuhp_remove_state(hyperv_cpuhp_online);
1507 hv_remove_vmbus_irq();
1509 bus_unregister(&hv_bus);
1510 unregister_sysctl_table(hv_ctl_table_hdr);
1511 hv_ctl_table_hdr = NULL;
1516 * __vmbus_child_driver_register() - Register a vmbus's driver
1517 * @hv_driver: Pointer to driver structure you want to register
1518 * @owner: owner module of the drv
1519 * @mod_name: module name string
1521 * Registers the given driver with Linux through the 'driver_register()' call
1522 * and sets up the hyper-v vmbus handling for this driver.
1523 * It will return the state of the 'driver_register()' call.
1526 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1530 pr_info("registering driver %s\n", hv_driver->name);
1532 ret = vmbus_exists();
1536 hv_driver->driver.name = hv_driver->name;
1537 hv_driver->driver.owner = owner;
1538 hv_driver->driver.mod_name = mod_name;
1539 hv_driver->driver.bus = &hv_bus;
1541 spin_lock_init(&hv_driver->dynids.lock);
1542 INIT_LIST_HEAD(&hv_driver->dynids.list);
1544 ret = driver_register(&hv_driver->driver);
1548 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1551 * vmbus_driver_unregister() - Unregister a vmbus's driver
1552 * @hv_driver: Pointer to driver structure you want to
1555 * Un-register the given driver that was previous registered with a call to
1556 * vmbus_driver_register()
1558 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1560 pr_info("unregistering driver %s\n", hv_driver->name);
1562 if (!vmbus_exists()) {
1563 driver_unregister(&hv_driver->driver);
1564 vmbus_free_dynids(hv_driver);
1567 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1571 * Called when last reference to channel is gone.
1573 static void vmbus_chan_release(struct kobject *kobj)
1575 struct vmbus_channel *channel
1576 = container_of(kobj, struct vmbus_channel, kobj);
1578 kfree_rcu(channel, rcu);
1581 struct vmbus_chan_attribute {
1582 struct attribute attr;
1583 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1584 ssize_t (*store)(struct vmbus_channel *chan,
1585 const char *buf, size_t count);
1587 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1588 struct vmbus_chan_attribute chan_attr_##_name \
1589 = __ATTR(_name, _mode, _show, _store)
1590 #define VMBUS_CHAN_ATTR_RW(_name) \
1591 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1592 #define VMBUS_CHAN_ATTR_RO(_name) \
1593 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1594 #define VMBUS_CHAN_ATTR_WO(_name) \
1595 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1597 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1598 struct attribute *attr, char *buf)
1600 const struct vmbus_chan_attribute *attribute
1601 = container_of(attr, struct vmbus_chan_attribute, attr);
1602 struct vmbus_channel *chan
1603 = container_of(kobj, struct vmbus_channel, kobj);
1605 if (!attribute->show)
1608 return attribute->show(chan, buf);
1611 static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1612 struct attribute *attr, const char *buf,
1615 const struct vmbus_chan_attribute *attribute
1616 = container_of(attr, struct vmbus_chan_attribute, attr);
1617 struct vmbus_channel *chan
1618 = container_of(kobj, struct vmbus_channel, kobj);
1620 if (!attribute->store)
1623 return attribute->store(chan, buf, count);
1626 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1627 .show = vmbus_chan_attr_show,
1628 .store = vmbus_chan_attr_store,
1631 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1633 struct hv_ring_buffer_info *rbi = &channel->outbound;
1636 mutex_lock(&rbi->ring_buffer_mutex);
1637 if (!rbi->ring_buffer) {
1638 mutex_unlock(&rbi->ring_buffer_mutex);
1642 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1643 mutex_unlock(&rbi->ring_buffer_mutex);
1646 static VMBUS_CHAN_ATTR_RO(out_mask);
1648 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1650 struct hv_ring_buffer_info *rbi = &channel->inbound;
1653 mutex_lock(&rbi->ring_buffer_mutex);
1654 if (!rbi->ring_buffer) {
1655 mutex_unlock(&rbi->ring_buffer_mutex);
1659 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1660 mutex_unlock(&rbi->ring_buffer_mutex);
1663 static VMBUS_CHAN_ATTR_RO(in_mask);
1665 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1667 struct hv_ring_buffer_info *rbi = &channel->inbound;
1670 mutex_lock(&rbi->ring_buffer_mutex);
1671 if (!rbi->ring_buffer) {
1672 mutex_unlock(&rbi->ring_buffer_mutex);
1676 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1677 mutex_unlock(&rbi->ring_buffer_mutex);
1680 static VMBUS_CHAN_ATTR_RO(read_avail);
1682 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1684 struct hv_ring_buffer_info *rbi = &channel->outbound;
1687 mutex_lock(&rbi->ring_buffer_mutex);
1688 if (!rbi->ring_buffer) {
1689 mutex_unlock(&rbi->ring_buffer_mutex);
1693 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1694 mutex_unlock(&rbi->ring_buffer_mutex);
1697 static VMBUS_CHAN_ATTR_RO(write_avail);
1699 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1701 return sprintf(buf, "%u\n", channel->target_cpu);
1703 static ssize_t target_cpu_store(struct vmbus_channel *channel,
1704 const char *buf, size_t count)
1706 u32 target_cpu, origin_cpu;
1707 ssize_t ret = count;
1709 if (vmbus_proto_version < VERSION_WIN10_V4_1)
1712 if (sscanf(buf, "%uu", &target_cpu) != 1)
1715 /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1716 if (target_cpu >= nr_cpumask_bits)
1719 /* No CPUs should come up or down during this. */
1722 if (!cpu_online(target_cpu)) {
1728 * Synchronizes target_cpu_store() and channel closure:
1730 * { Initially: state = CHANNEL_OPENED }
1734 * [target_cpu_store()] [vmbus_disconnect_ring()]
1736 * LOCK channel_mutex LOCK channel_mutex
1737 * LOAD r1 = state LOAD r2 = state
1738 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
1739 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
1740 * [...] SEND CLOSECHANNEL
1741 * UNLOCK channel_mutex UNLOCK channel_mutex
1743 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1744 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1746 * Note. The host processes the channel messages "sequentially", in
1747 * the order in which they are received on a per-partition basis.
1749 mutex_lock(&vmbus_connection.channel_mutex);
1752 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1753 * avoid sending the message and fail here for such channels.
1755 if (channel->state != CHANNEL_OPENED_STATE) {
1757 goto cpu_store_unlock;
1760 origin_cpu = channel->target_cpu;
1761 if (target_cpu == origin_cpu)
1762 goto cpu_store_unlock;
1764 if (vmbus_send_modifychannel(channel->offermsg.child_relid,
1765 hv_cpu_number_to_vp_number(target_cpu))) {
1767 goto cpu_store_unlock;
1771 * Warning. At this point, there is *no* guarantee that the host will
1772 * have successfully processed the vmbus_send_modifychannel() request.
1773 * See the header comment of vmbus_send_modifychannel() for more info.
1775 * Lags in the processing of the above vmbus_send_modifychannel() can
1776 * result in missed interrupts if the "old" target CPU is taken offline
1777 * before Hyper-V starts sending interrupts to the "new" target CPU.
1778 * But apart from this offlining scenario, the code tolerates such
1779 * lags. It will function correctly even if a channel interrupt comes
1780 * in on a CPU that is different from the channel target_cpu value.
1783 channel->target_cpu = target_cpu;
1785 /* See init_vp_index(). */
1786 if (hv_is_perf_channel(channel))
1787 hv_update_alloced_cpus(origin_cpu, target_cpu);
1789 /* Currently set only for storvsc channels. */
1790 if (channel->change_target_cpu_callback) {
1791 (*channel->change_target_cpu_callback)(channel,
1792 origin_cpu, target_cpu);
1796 mutex_unlock(&vmbus_connection.channel_mutex);
1800 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1802 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1805 return sprintf(buf, "%d\n",
1806 channel_pending(channel,
1807 vmbus_connection.monitor_pages[1]));
1809 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1811 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1814 return sprintf(buf, "%d\n",
1815 channel_latency(channel,
1816 vmbus_connection.monitor_pages[1]));
1818 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1820 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1822 return sprintf(buf, "%llu\n", channel->interrupts);
1824 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1826 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1828 return sprintf(buf, "%llu\n", channel->sig_events);
1830 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1832 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1835 return sprintf(buf, "%llu\n",
1836 (unsigned long long)channel->intr_in_full);
1838 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1840 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1843 return sprintf(buf, "%llu\n",
1844 (unsigned long long)channel->intr_out_empty);
1846 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1848 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1851 return sprintf(buf, "%llu\n",
1852 (unsigned long long)channel->out_full_first);
1854 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1856 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1859 return sprintf(buf, "%llu\n",
1860 (unsigned long long)channel->out_full_total);
1862 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1864 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1867 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1869 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1871 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1874 return sprintf(buf, "%u\n",
1875 channel->offermsg.offer.sub_channel_index);
1877 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1879 static struct attribute *vmbus_chan_attrs[] = {
1880 &chan_attr_out_mask.attr,
1881 &chan_attr_in_mask.attr,
1882 &chan_attr_read_avail.attr,
1883 &chan_attr_write_avail.attr,
1884 &chan_attr_cpu.attr,
1885 &chan_attr_pending.attr,
1886 &chan_attr_latency.attr,
1887 &chan_attr_interrupts.attr,
1888 &chan_attr_events.attr,
1889 &chan_attr_intr_in_full.attr,
1890 &chan_attr_intr_out_empty.attr,
1891 &chan_attr_out_full_first.attr,
1892 &chan_attr_out_full_total.attr,
1893 &chan_attr_monitor_id.attr,
1894 &chan_attr_subchannel_id.attr,
1899 * Channel-level attribute_group callback function. Returns the permission for
1900 * each attribute, and returns 0 if an attribute is not visible.
1902 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1903 struct attribute *attr, int idx)
1905 const struct vmbus_channel *channel =
1906 container_of(kobj, struct vmbus_channel, kobj);
1908 /* Hide the monitor attributes if the monitor mechanism is not used. */
1909 if (!channel->offermsg.monitor_allocated &&
1910 (attr == &chan_attr_pending.attr ||
1911 attr == &chan_attr_latency.attr ||
1912 attr == &chan_attr_monitor_id.attr))
1918 static struct attribute_group vmbus_chan_group = {
1919 .attrs = vmbus_chan_attrs,
1920 .is_visible = vmbus_chan_attr_is_visible
1923 static struct kobj_type vmbus_chan_ktype = {
1924 .sysfs_ops = &vmbus_chan_sysfs_ops,
1925 .release = vmbus_chan_release,
1929 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1931 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1933 const struct device *device = &dev->device;
1934 struct kobject *kobj = &channel->kobj;
1935 u32 relid = channel->offermsg.child_relid;
1938 kobj->kset = dev->channels_kset;
1939 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1944 ret = sysfs_create_group(kobj, &vmbus_chan_group);
1948 * The calling functions' error handling paths will cleanup the
1949 * empty channel directory.
1951 dev_err(device, "Unable to set up channel sysfs files\n");
1955 kobject_uevent(kobj, KOBJ_ADD);
1961 * vmbus_remove_channel_attr_group - remove the channel's attribute group
1963 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1965 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1969 * vmbus_device_create - Creates and registers a new child device
1972 struct hv_device *vmbus_device_create(const guid_t *type,
1973 const guid_t *instance,
1974 struct vmbus_channel *channel)
1976 struct hv_device *child_device_obj;
1978 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1979 if (!child_device_obj) {
1980 pr_err("Unable to allocate device object for child device\n");
1984 child_device_obj->channel = channel;
1985 guid_copy(&child_device_obj->dev_type, type);
1986 guid_copy(&child_device_obj->dev_instance, instance);
1987 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1989 return child_device_obj;
1993 * vmbus_device_register - Register the child device
1995 int vmbus_device_register(struct hv_device *child_device_obj)
1997 struct kobject *kobj = &child_device_obj->device.kobj;
2000 dev_set_name(&child_device_obj->device, "%pUl",
2001 &child_device_obj->channel->offermsg.offer.if_instance);
2003 child_device_obj->device.bus = &hv_bus;
2004 child_device_obj->device.parent = &hv_acpi_dev->dev;
2005 child_device_obj->device.release = vmbus_device_release;
2008 * Register with the LDM. This will kick off the driver/device
2009 * binding...which will eventually call vmbus_match() and vmbus_probe()
2011 ret = device_register(&child_device_obj->device);
2013 pr_err("Unable to register child device\n");
2017 child_device_obj->channels_kset = kset_create_and_add("channels",
2019 if (!child_device_obj->channels_kset) {
2021 goto err_dev_unregister;
2024 ret = vmbus_add_channel_kobj(child_device_obj,
2025 child_device_obj->channel);
2027 pr_err("Unable to register primary channeln");
2028 goto err_kset_unregister;
2030 hv_debug_add_dev_dir(child_device_obj);
2034 err_kset_unregister:
2035 kset_unregister(child_device_obj->channels_kset);
2038 device_unregister(&child_device_obj->device);
2043 * vmbus_device_unregister - Remove the specified child device
2046 void vmbus_device_unregister(struct hv_device *device_obj)
2048 pr_debug("child device %s unregistered\n",
2049 dev_name(&device_obj->device));
2051 kset_unregister(device_obj->channels_kset);
2054 * Kick off the process of unregistering the device.
2055 * This will call vmbus_remove() and eventually vmbus_device_release()
2057 device_unregister(&device_obj->device);
2062 * VMBUS is an acpi enumerated device. Get the information we
2065 #define VTPM_BASE_ADDRESS 0xfed40000
2066 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2068 resource_size_t start = 0;
2069 resource_size_t end = 0;
2070 struct resource *new_res;
2071 struct resource **old_res = &hyperv_mmio;
2072 struct resource **prev_res = NULL;
2074 switch (res->type) {
2077 * "Address" descriptors are for bus windows. Ignore
2078 * "memory" descriptors, which are for registers on
2081 case ACPI_RESOURCE_TYPE_ADDRESS32:
2082 start = res->data.address32.address.minimum;
2083 end = res->data.address32.address.maximum;
2086 case ACPI_RESOURCE_TYPE_ADDRESS64:
2087 start = res->data.address64.address.minimum;
2088 end = res->data.address64.address.maximum;
2092 /* Unused resource type */
2097 * Ignore ranges that are below 1MB, as they're not
2098 * necessary or useful here.
2103 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2105 return AE_NO_MEMORY;
2107 /* If this range overlaps the virtual TPM, truncate it. */
2108 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2109 end = VTPM_BASE_ADDRESS;
2111 new_res->name = "hyperv mmio";
2112 new_res->flags = IORESOURCE_MEM;
2113 new_res->start = start;
2117 * If two ranges are adjacent, merge them.
2125 if (((*old_res)->end + 1) == new_res->start) {
2126 (*old_res)->end = new_res->end;
2131 if ((*old_res)->start == new_res->end + 1) {
2132 (*old_res)->start = new_res->start;
2137 if ((*old_res)->start > new_res->end) {
2138 new_res->sibling = *old_res;
2140 (*prev_res)->sibling = new_res;
2146 old_res = &(*old_res)->sibling;
2153 static int vmbus_acpi_remove(struct acpi_device *device)
2155 struct resource *cur_res;
2156 struct resource *next_res;
2160 __release_region(hyperv_mmio, fb_mmio->start,
2161 resource_size(fb_mmio));
2165 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2166 next_res = cur_res->sibling;
2174 static void vmbus_reserve_fb(void)
2178 * Make a claim for the frame buffer in the resource tree under the
2179 * first node, which will be the one below 4GB. The length seems to
2180 * be underreported, particularly in a Generation 1 VM. So start out
2181 * reserving a larger area and make it smaller until it succeeds.
2184 if (screen_info.lfb_base) {
2185 if (efi_enabled(EFI_BOOT))
2186 size = max_t(__u32, screen_info.lfb_size, 0x800000);
2188 size = max_t(__u32, screen_info.lfb_size, 0x4000000);
2190 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
2191 fb_mmio = __request_region(hyperv_mmio,
2192 screen_info.lfb_base, size,
2199 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2200 * @new: If successful, supplied a pointer to the
2201 * allocated MMIO space.
2202 * @device_obj: Identifies the caller
2203 * @min: Minimum guest physical address of the
2205 * @max: Maximum guest physical address
2206 * @size: Size of the range to be allocated
2207 * @align: Alignment of the range to be allocated
2208 * @fb_overlap_ok: Whether this allocation can be allowed
2209 * to overlap the video frame buffer.
2211 * This function walks the resources granted to VMBus by the
2212 * _CRS object in the ACPI namespace underneath the parent
2213 * "bridge" whether that's a root PCI bus in the Generation 1
2214 * case or a Module Device in the Generation 2 case. It then
2215 * attempts to allocate from the global MMIO pool in a way that
2216 * matches the constraints supplied in these parameters and by
2219 * Return: 0 on success, -errno on failure
2221 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2222 resource_size_t min, resource_size_t max,
2223 resource_size_t size, resource_size_t align,
2226 struct resource *iter, *shadow;
2227 resource_size_t range_min, range_max, start;
2228 const char *dev_n = dev_name(&device_obj->device);
2232 mutex_lock(&hyperv_mmio_lock);
2235 * If overlaps with frame buffers are allowed, then first attempt to
2236 * make the allocation from within the reserved region. Because it
2237 * is already reserved, no shadow allocation is necessary.
2239 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2240 !(max < fb_mmio->start)) {
2242 range_min = fb_mmio->start;
2243 range_max = fb_mmio->end;
2244 start = (range_min + align - 1) & ~(align - 1);
2245 for (; start + size - 1 <= range_max; start += align) {
2246 *new = request_mem_region_exclusive(start, size, dev_n);
2254 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2255 if ((iter->start >= max) || (iter->end <= min))
2258 range_min = iter->start;
2259 range_max = iter->end;
2260 start = (range_min + align - 1) & ~(align - 1);
2261 for (; start + size - 1 <= range_max; start += align) {
2262 shadow = __request_region(iter, start, size, NULL,
2267 *new = request_mem_region_exclusive(start, size, dev_n);
2269 shadow->name = (char *)*new;
2274 __release_region(iter, start, size);
2279 mutex_unlock(&hyperv_mmio_lock);
2282 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2285 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2286 * @start: Base address of region to release.
2287 * @size: Size of the range to be allocated
2289 * This function releases anything requested by
2290 * vmbus_mmio_allocate().
2292 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2294 struct resource *iter;
2296 mutex_lock(&hyperv_mmio_lock);
2297 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2298 if ((iter->start >= start + size) || (iter->end <= start))
2301 __release_region(iter, start, size);
2303 release_mem_region(start, size);
2304 mutex_unlock(&hyperv_mmio_lock);
2307 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2309 static int vmbus_acpi_add(struct acpi_device *device)
2312 int ret_val = -ENODEV;
2313 struct acpi_device *ancestor;
2315 hv_acpi_dev = device;
2317 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2318 vmbus_walk_resources, NULL);
2320 if (ACPI_FAILURE(result))
2323 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2324 * firmware) is the VMOD that has the mmio ranges. Get that.
2326 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2327 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2328 vmbus_walk_resources, NULL);
2330 if (ACPI_FAILURE(result))
2340 complete(&probe_event);
2342 vmbus_acpi_remove(device);
2346 #ifdef CONFIG_PM_SLEEP
2347 static int vmbus_bus_suspend(struct device *dev)
2349 struct vmbus_channel *channel, *sc;
2351 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2353 * We wait here until the completion of any channel
2354 * offers that are currently in progress.
2359 mutex_lock(&vmbus_connection.channel_mutex);
2360 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2361 if (!is_hvsock_channel(channel))
2364 vmbus_force_channel_rescinded(channel);
2366 mutex_unlock(&vmbus_connection.channel_mutex);
2369 * Wait until all the sub-channels and hv_sock channels have been
2370 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2371 * they would conflict with the new sub-channels that will be created
2372 * in the resume path. hv_sock channels should also be destroyed, but
2373 * a hv_sock channel of an established hv_sock connection can not be
2374 * really destroyed since it may still be referenced by the userspace
2375 * application, so we just force the hv_sock channel to be rescinded
2376 * by vmbus_force_channel_rescinded(), and the userspace application
2377 * will thoroughly destroy the channel after hibernation.
2379 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2380 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2382 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2383 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2385 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
2387 mutex_lock(&vmbus_connection.channel_mutex);
2389 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2391 * Remove the channel from the array of channels and invalidate
2392 * the channel's relid. Upon resume, vmbus_onoffer() will fix
2393 * up the relid (and other fields, if necessary) and add the
2394 * channel back to the array.
2396 vmbus_channel_unmap_relid(channel);
2397 channel->offermsg.child_relid = INVALID_RELID;
2399 if (is_hvsock_channel(channel)) {
2400 if (!channel->rescind) {
2401 pr_err("hv_sock channel not rescinded!\n");
2407 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2408 pr_err("Sub-channel not deleted!\n");
2412 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2415 mutex_unlock(&vmbus_connection.channel_mutex);
2417 vmbus_initiate_unload(false);
2419 /* Reset the event for the next resume. */
2420 reinit_completion(&vmbus_connection.ready_for_resume_event);
2425 static int vmbus_bus_resume(struct device *dev)
2427 struct vmbus_channel_msginfo *msginfo;
2432 * We only use the 'vmbus_proto_version', which was in use before
2433 * hibernation, to re-negotiate with the host.
2435 if (!vmbus_proto_version) {
2436 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2440 msgsize = sizeof(*msginfo) +
2441 sizeof(struct vmbus_channel_initiate_contact);
2443 msginfo = kzalloc(msgsize, GFP_KERNEL);
2445 if (msginfo == NULL)
2448 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2455 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2457 vmbus_request_offers();
2459 wait_for_completion(&vmbus_connection.ready_for_resume_event);
2461 /* Reset the event for the next suspend. */
2462 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2467 #define vmbus_bus_suspend NULL
2468 #define vmbus_bus_resume NULL
2469 #endif /* CONFIG_PM_SLEEP */
2471 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2476 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2479 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2480 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2481 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2482 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2483 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2484 * resume callback must also run via the "noirq" ops.
2486 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2487 * earlier in this file before vmbus_pm.
2490 static const struct dev_pm_ops vmbus_bus_pm = {
2491 .suspend_noirq = NULL,
2492 .resume_noirq = NULL,
2493 .freeze_noirq = vmbus_bus_suspend,
2494 .thaw_noirq = vmbus_bus_resume,
2495 .poweroff_noirq = vmbus_bus_suspend,
2496 .restore_noirq = vmbus_bus_resume
2499 static struct acpi_driver vmbus_acpi_driver = {
2501 .ids = vmbus_acpi_device_ids,
2503 .add = vmbus_acpi_add,
2504 .remove = vmbus_acpi_remove,
2506 .drv.pm = &vmbus_bus_pm,
2509 static void hv_kexec_handler(void)
2511 hv_stimer_global_cleanup();
2512 vmbus_initiate_unload(false);
2513 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2515 cpuhp_remove_state(hyperv_cpuhp_online);
2519 static void hv_crash_handler(struct pt_regs *regs)
2523 vmbus_initiate_unload(true);
2525 * In crash handler we can't schedule synic cleanup for all CPUs,
2526 * doing the cleanup for current CPU only. This should be sufficient
2529 cpu = smp_processor_id();
2530 hv_stimer_cleanup(cpu);
2531 hv_synic_disable_regs(cpu);
2535 static int hv_synic_suspend(void)
2538 * When we reach here, all the non-boot CPUs have been offlined.
2539 * If we're in a legacy configuration where stimer Direct Mode is
2540 * not enabled, the stimers on the non-boot CPUs have been unbound
2541 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2542 * hv_stimer_cleanup() -> clockevents_unbind_device().
2544 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2545 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2546 * 1) it's unnecessary as interrupts remain disabled between
2547 * syscore_suspend() and syscore_resume(): see create_image() and
2548 * resume_target_kernel()
2549 * 2) the stimer on CPU0 is automatically disabled later by
2550 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2551 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2552 * 3) a warning would be triggered if we call
2553 * clockevents_unbind_device(), which may sleep, in an
2554 * interrupts-disabled context.
2557 hv_synic_disable_regs(0);
2562 static void hv_synic_resume(void)
2564 hv_synic_enable_regs(0);
2567 * Note: we don't need to call hv_stimer_init(0), because the timer
2568 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2569 * automatically re-enabled in timekeeping_resume().
2573 /* The callbacks run only on CPU0, with irqs_disabled. */
2574 static struct syscore_ops hv_synic_syscore_ops = {
2575 .suspend = hv_synic_suspend,
2576 .resume = hv_synic_resume,
2579 static int __init hv_acpi_init(void)
2583 if (!hv_is_hyperv_initialized())
2586 init_completion(&probe_event);
2589 * Get ACPI resources first.
2591 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2596 t = wait_for_completion_timeout(&probe_event, 5*HZ);
2603 ret = vmbus_bus_init();
2607 hv_setup_kexec_handler(hv_kexec_handler);
2608 hv_setup_crash_handler(hv_crash_handler);
2610 register_syscore_ops(&hv_synic_syscore_ops);
2615 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2620 static void __exit vmbus_exit(void)
2624 unregister_syscore_ops(&hv_synic_syscore_ops);
2626 hv_remove_kexec_handler();
2627 hv_remove_crash_handler();
2628 vmbus_connection.conn_state = DISCONNECTED;
2629 hv_stimer_global_cleanup();
2631 hv_remove_vmbus_irq();
2632 for_each_online_cpu(cpu) {
2633 struct hv_per_cpu_context *hv_cpu
2634 = per_cpu_ptr(hv_context.cpu_context, cpu);
2636 tasklet_kill(&hv_cpu->msg_dpc);
2638 hv_debug_rm_all_dir();
2640 vmbus_free_channels();
2641 kfree(vmbus_connection.channels);
2643 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2644 kmsg_dump_unregister(&hv_kmsg_dumper);
2645 unregister_die_notifier(&hyperv_die_block);
2646 atomic_notifier_chain_unregister(&panic_notifier_list,
2647 &hyperv_panic_block);
2650 free_page((unsigned long)hv_panic_page);
2651 unregister_sysctl_table(hv_ctl_table_hdr);
2652 hv_ctl_table_hdr = NULL;
2653 bus_unregister(&hv_bus);
2655 cpuhp_remove_state(hyperv_cpuhp_online);
2657 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2661 MODULE_LICENSE("GPL");
2662 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2664 subsys_initcall(hv_acpi_init);
2665 module_exit(vmbus_exit);