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linux-sg2042/drivers/hv/vmbus_drv.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2009, Microsoft Corporation.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
* K. Y. Srinivasan <kys@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/hyperv.h>
#include <linux/kernel_stat.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/sched/task_stack.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/panic_notifier.h>
#include <linux/ptrace.h>
#include <linux/screen_info.h>
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
#include <linux/kernel.h>
#include <linux/syscore_ops.h>
#include <linux/dma-map-ops.h>
#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
struct vmbus_dynid {
struct list_head node;
struct hv_vmbus_device_id id;
};
static struct acpi_device *hv_acpi_dev;
static struct completion probe_event;
static int hyperv_cpuhp_online;
static void *hv_panic_page;
static long __percpu *vmbus_evt;
/* Values parsed from ACPI DSDT */
int vmbus_irq;
int vmbus_interrupt;
/*
* Boolean to control whether to report panic messages over Hyper-V.
*
* It can be set via /proc/sys/kernel/hyperv_record_panic_msg
*/
static int sysctl_record_panic_msg = 1;
static int hyperv_report_reg(void)
{
return !sysctl_record_panic_msg || !hv_panic_page;
}
static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct pt_regs *regs;
vmbus_initiate_unload(true);
/*
* Hyper-V should be notified only once about a panic. If we will be
* doing hv_kmsg_dump() with kmsg data later, don't do the notification
* here.
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
&& hyperv_report_reg()) {
regs = current_pt_regs();
hyperv_report_panic(regs, val, false);
}
return NOTIFY_DONE;
}
static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct die_args *die = args;
struct pt_regs *regs = die->regs;
/* Don't notify Hyper-V if the die event is other than oops */
if (val != DIE_OOPS)
return NOTIFY_DONE;
/*
* Hyper-V should be notified only once about a panic. If we will be
* doing hv_kmsg_dump() with kmsg data later, don't do the notification
* here.
*/
if (hyperv_report_reg())
hyperv_report_panic(regs, val, true);
return NOTIFY_DONE;
}
static struct notifier_block hyperv_die_block = {
.notifier_call = hyperv_die_event,
};
static struct notifier_block hyperv_panic_block = {
.notifier_call = hyperv_panic_event,
};
static const char *fb_mmio_name = "fb_range";
static struct resource *fb_mmio;
static struct resource *hyperv_mmio;
static DEFINE_MUTEX(hyperv_mmio_lock);
static int vmbus_exists(void)
{
if (hv_acpi_dev == NULL)
return -ENODEV;
return 0;
}
static u8 channel_monitor_group(const struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid / 32;
}
static u8 channel_monitor_offset(const struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid % 32;
}
static u32 channel_pending(const struct vmbus_channel *channel,
const struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
return monitor_page->trigger_group[monitor_group].pending;
}
static u32 channel_latency(const struct vmbus_channel *channel,
const struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
u8 monitor_offset = channel_monitor_offset(channel);
return monitor_page->latency[monitor_group][monitor_offset];
}
static u32 channel_conn_id(struct vmbus_channel *channel,
struct hv_monitor_page *monitor_page)
{
u8 monitor_group = channel_monitor_group(channel);
u8 monitor_offset = channel_monitor_offset(channel);
return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
}
static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
}
static DEVICE_ATTR_RO(id);
static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->state);
}
static DEVICE_ATTR_RO(state);
static ssize_t monitor_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
}
static DEVICE_ATTR_RO(monitor_id);
static ssize_t class_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "{%pUl}\n",
&hv_dev->channel->offermsg.offer.if_type);
}
static DEVICE_ATTR_RO(class_id);
static ssize_t device_id_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "{%pUl}\n",
&hv_dev->channel->offermsg.offer.if_instance);
}
static DEVICE_ATTR_RO(device_id);
static ssize_t modalias_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
}
static DEVICE_ATTR_RO(modalias);
#ifdef CONFIG_NUMA
static ssize_t numa_node_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
}
static DEVICE_ATTR_RO(numa_node);
#endif
static ssize_t server_monitor_pending_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_pending(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_pending);
static ssize_t client_monitor_pending_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_pending(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_pending);
static ssize_t server_monitor_latency_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_latency(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_latency);
static ssize_t client_monitor_latency_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_latency(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_latency);
static ssize_t server_monitor_conn_id_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_conn_id(hv_dev->channel,
vmbus_connection.monitor_pages[0]));
}
static DEVICE_ATTR_RO(server_monitor_conn_id);
static ssize_t client_monitor_conn_id_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
if (!hv_dev->channel)
return -ENODEV;
return sprintf(buf, "%d\n",
channel_conn_id(hv_dev->channel,
vmbus_connection.monitor_pages[1]));
}
static DEVICE_ATTR_RO(client_monitor_conn_id);
static ssize_t out_intr_mask_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
}
static DEVICE_ATTR_RO(out_intr_mask);
static ssize_t out_read_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_read_index);
}
static DEVICE_ATTR_RO(out_read_index);
static ssize_t out_write_index_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.current_write_index);
}
static DEVICE_ATTR_RO(out_write_index);
static ssize_t out_read_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
}
static DEVICE_ATTR_RO(out_read_bytes_avail);
static ssize_t out_write_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info outbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
&outbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
}
static DEVICE_ATTR_RO(out_write_bytes_avail);
static ssize_t in_intr_mask_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
}
static DEVICE_ATTR_RO(in_intr_mask);
static ssize_t in_read_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_read_index);
}
static DEVICE_ATTR_RO(in_read_index);
static ssize_t in_write_index_show(struct device *dev,
struct device_attribute *dev_attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.current_write_index);
}
static DEVICE_ATTR_RO(in_write_index);
static ssize_t in_read_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
}
static DEVICE_ATTR_RO(in_read_bytes_avail);
static ssize_t in_write_bytes_avail_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_ring_buffer_debug_info inbound;
int ret;
if (!hv_dev->channel)
return -ENODEV;
ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
}
static DEVICE_ATTR_RO(in_write_bytes_avail);
static ssize_t channel_vp_mapping_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
int buf_size = PAGE_SIZE, n_written, tot_written;
struct list_head *cur;
if (!channel)
return -ENODEV;
mutex_lock(&vmbus_connection.channel_mutex);
tot_written = snprintf(buf, buf_size, "%u:%u\n",
channel->offermsg.child_relid, channel->target_cpu);
list_for_each(cur, &channel->sc_list) {
if (tot_written >= buf_size - 1)
break;
cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
n_written = scnprintf(buf + tot_written,
buf_size - tot_written,
"%u:%u\n",
cur_sc->offermsg.child_relid,
cur_sc->target_cpu);
tot_written += n_written;
}
mutex_unlock(&vmbus_connection.channel_mutex);
return tot_written;
}
static DEVICE_ATTR_RO(channel_vp_mapping);
static ssize_t vendor_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
}
static DEVICE_ATTR_RO(vendor);
static ssize_t device_show(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
return sprintf(buf, "0x%x\n", hv_dev->device_id);
}
static DEVICE_ATTR_RO(device);
static ssize_t driver_override_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
int ret;
ret = driver_set_override(dev, &hv_dev->driver_override, buf, count);
if (ret)
return ret;
return count;
}
static ssize_t driver_override_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
ssize_t len;
device_lock(dev);
len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
device_unlock(dev);
return len;
}
static DEVICE_ATTR_RW(driver_override);
/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
static struct attribute *vmbus_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_state.attr,
&dev_attr_monitor_id.attr,
&dev_attr_class_id.attr,
&dev_attr_device_id.attr,
&dev_attr_modalias.attr,
#ifdef CONFIG_NUMA
&dev_attr_numa_node.attr,
#endif
&dev_attr_server_monitor_pending.attr,
&dev_attr_client_monitor_pending.attr,
&dev_attr_server_monitor_latency.attr,
&dev_attr_client_monitor_latency.attr,
&dev_attr_server_monitor_conn_id.attr,
&dev_attr_client_monitor_conn_id.attr,
&dev_attr_out_intr_mask.attr,
&dev_attr_out_read_index.attr,
&dev_attr_out_write_index.attr,
&dev_attr_out_read_bytes_avail.attr,
&dev_attr_out_write_bytes_avail.attr,
&dev_attr_in_intr_mask.attr,
&dev_attr_in_read_index.attr,
&dev_attr_in_write_index.attr,
&dev_attr_in_read_bytes_avail.attr,
&dev_attr_in_write_bytes_avail.attr,
&dev_attr_channel_vp_mapping.attr,
&dev_attr_vendor.attr,
&dev_attr_device.attr,
&dev_attr_driver_override.attr,
NULL,
};
/*
* Device-level attribute_group callback function. Returns the permission for
* each attribute, and returns 0 if an attribute is not visible.
*/
static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
struct device *dev = kobj_to_dev(kobj);
const struct hv_device *hv_dev = device_to_hv_device(dev);
/* Hide the monitor attributes if the monitor mechanism is not used. */
if (!hv_dev->channel->offermsg.monitor_allocated &&
(attr == &dev_attr_monitor_id.attr ||
attr == &dev_attr_server_monitor_pending.attr ||
attr == &dev_attr_client_monitor_pending.attr ||
attr == &dev_attr_server_monitor_latency.attr ||
attr == &dev_attr_client_monitor_latency.attr ||
attr == &dev_attr_server_monitor_conn_id.attr ||
attr == &dev_attr_client_monitor_conn_id.attr))
return 0;
return attr->mode;
}
static const struct attribute_group vmbus_dev_group = {
.attrs = vmbus_dev_attrs,
.is_visible = vmbus_dev_attr_is_visible
};
__ATTRIBUTE_GROUPS(vmbus_dev);
/* Set up the attribute for /sys/bus/vmbus/hibernation */
static ssize_t hibernation_show(struct bus_type *bus, char *buf)
{
return sprintf(buf, "%d\n", !!hv_is_hibernation_supported());
}
static BUS_ATTR_RO(hibernation);
static struct attribute *vmbus_bus_attrs[] = {
&bus_attr_hibernation.attr,
NULL,
};
static const struct attribute_group vmbus_bus_group = {
.attrs = vmbus_bus_attrs,
};
__ATTRIBUTE_GROUPS(vmbus_bus);
/*
* vmbus_uevent - add uevent for our device
*
* This routine is invoked when a device is added or removed on the vmbus to
* generate a uevent to udev in the userspace. The udev will then look at its
* rule and the uevent generated here to load the appropriate driver
*
* The alias string will be of the form vmbus:guid where guid is the string
* representation of the device guid (each byte of the guid will be
* represented with two hex characters.
*/
static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
{
struct hv_device *dev = device_to_hv_device(device);
const char *format = "MODALIAS=vmbus:%*phN";
return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
}
static const struct hv_vmbus_device_id *
hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
{
if (id == NULL)
return NULL; /* empty device table */
for (; !guid_is_null(&id->guid); id++)
if (guid_equal(&id->guid, guid))
return id;
return NULL;
}
static const struct hv_vmbus_device_id *
hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
{
const struct hv_vmbus_device_id *id = NULL;
struct vmbus_dynid *dynid;
spin_lock(&drv->dynids.lock);
list_for_each_entry(dynid, &drv->dynids.list, node) {
if (guid_equal(&dynid->id.guid, guid)) {
id = &dynid->id;
break;
}
}
spin_unlock(&drv->dynids.lock);
return id;
}
static const struct hv_vmbus_device_id vmbus_device_null;
/*
* Return a matching hv_vmbus_device_id pointer.
* If there is no match, return NULL.
*/
static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
struct hv_device *dev)
{
const guid_t *guid = &dev->dev_type;
const struct hv_vmbus_device_id *id;
/* When driver_override is set, only bind to the matching driver */
if (dev->driver_override && strcmp(dev->driver_override, drv->name))
return NULL;
/* Look at the dynamic ids first, before the static ones */
id = hv_vmbus_dynid_match(drv, guid);
if (!id)
id = hv_vmbus_dev_match(drv->id_table, guid);
/* driver_override will always match, send a dummy id */
if (!id && dev->driver_override)
id = &vmbus_device_null;
return id;
}
/* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
{
struct vmbus_dynid *dynid;
dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
if (!dynid)
return -ENOMEM;
dynid->id.guid = *guid;
spin_lock(&drv->dynids.lock);
list_add_tail(&dynid->node, &drv->dynids.list);
spin_unlock(&drv->dynids.lock);
return driver_attach(&drv->driver);
}
static void vmbus_free_dynids(struct hv_driver *drv)
{
struct vmbus_dynid *dynid, *n;
spin_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
list_del(&dynid->node);
kfree(dynid);
}
spin_unlock(&drv->dynids.lock);
}
/*
* store_new_id - sysfs frontend to vmbus_add_dynid()
*
* Allow GUIDs to be added to an existing driver via sysfs.
*/
static ssize_t new_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
guid_t guid;
ssize_t retval;
retval = guid_parse(buf, &guid);
if (retval)
return retval;
if (hv_vmbus_dynid_match(drv, &guid))
return -EEXIST;
retval = vmbus_add_dynid(drv, &guid);
if (retval)
return retval;
return count;
}
static DRIVER_ATTR_WO(new_id);
/*
* store_remove_id - remove a PCI device ID from this driver
*
* Removes a dynamic pci device ID to this driver.
*/
static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
struct vmbus_dynid *dynid, *n;
guid_t guid;
ssize_t retval;
retval = guid_parse(buf, &guid);
if (retval)
return retval;
retval = -ENODEV;
spin_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
struct hv_vmbus_device_id *id = &dynid->id;
if (guid_equal(&id->guid, &guid)) {
list_del(&dynid->node);
kfree(dynid);
retval = count;
break;
}
}
spin_unlock(&drv->dynids.lock);
return retval;
}
static DRIVER_ATTR_WO(remove_id);
static struct attribute *vmbus_drv_attrs[] = {
&driver_attr_new_id.attr,
&driver_attr_remove_id.attr,
NULL,
};
ATTRIBUTE_GROUPS(vmbus_drv);
/*
* vmbus_match - Attempt to match the specified device to the specified driver
*/
static int vmbus_match(struct device *device, struct device_driver *driver)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
struct hv_device *hv_dev = device_to_hv_device(device);
/* The hv_sock driver handles all hv_sock offers. */
if (is_hvsock_channel(hv_dev->channel))
return drv->hvsock;
if (hv_vmbus_get_id(drv, hv_dev))
return 1;
return 0;
}
/*
* vmbus_probe - Add the new vmbus's child device
*/
static int vmbus_probe(struct device *child_device)
{
int ret = 0;
struct hv_driver *drv =
drv_to_hv_drv(child_device->driver);
struct hv_device *dev = device_to_hv_device(child_device);
const struct hv_vmbus_device_id *dev_id;
dev_id = hv_vmbus_get_id(drv, dev);
if (drv->probe) {
ret = drv->probe(dev, dev_id);
if (ret != 0)
pr_err("probe failed for device %s (%d)\n",
dev_name(child_device), ret);
} else {
pr_err("probe not set for driver %s\n",
dev_name(child_device));
ret = -ENODEV;
}
return ret;
}
/*
* vmbus_dma_configure -- Configure DMA coherence for VMbus device
*/
static int vmbus_dma_configure(struct device *child_device)
{
/*
* On ARM64, propagate the DMA coherence setting from the top level
* VMbus ACPI device to the child VMbus device being added here.
* On x86/x64 coherence is assumed and these calls have no effect.
*/
hv_setup_dma_ops(child_device,
device_get_dma_attr(&hv_acpi_dev->dev) == DEV_DMA_COHERENT);
return 0;
}
/*
* vmbus_remove - Remove a vmbus device
*/
static void vmbus_remove(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
if (child_device->driver) {
drv = drv_to_hv_drv(child_device->driver);
if (drv->remove)
drv->remove(dev);
}
}
/*
* vmbus_shutdown - Shutdown a vmbus device
*/
static void vmbus_shutdown(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return;
drv = drv_to_hv_drv(child_device->driver);
if (drv->shutdown)
drv->shutdown(dev);
}
#ifdef CONFIG_PM_SLEEP
/*
* vmbus_suspend - Suspend a vmbus device
*/
static int vmbus_suspend(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return 0;
drv = drv_to_hv_drv(child_device->driver);
if (!drv->suspend)
return -EOPNOTSUPP;
return drv->suspend(dev);
}
/*
* vmbus_resume - Resume a vmbus device
*/
static int vmbus_resume(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return 0;
drv = drv_to_hv_drv(child_device->driver);
if (!drv->resume)
return -EOPNOTSUPP;
return drv->resume(dev);
}
#else
#define vmbus_suspend NULL
#define vmbus_resume NULL
#endif /* CONFIG_PM_SLEEP */
/*
* vmbus_device_release - Final callback release of the vmbus child device
*/
static void vmbus_device_release(struct device *device)
{
struct hv_device *hv_dev = device_to_hv_device(device);
struct vmbus_channel *channel = hv_dev->channel;
hv_debug_rm_dev_dir(hv_dev);
mutex_lock(&vmbus_connection.channel_mutex);
hv_process_channel_removal(channel);
mutex_unlock(&vmbus_connection.channel_mutex);
kfree(hv_dev);
}
/*
* Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
*
* suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
* shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
* is no way to wake up a Generation-2 VM.
*
* The other 4 ops are for hibernation.
*/
static const struct dev_pm_ops vmbus_pm = {
.suspend_noirq = NULL,
.resume_noirq = NULL,
.freeze_noirq = vmbus_suspend,
.thaw_noirq = vmbus_resume,
.poweroff_noirq = vmbus_suspend,
.restore_noirq = vmbus_resume,
};
/* The one and only one */
static struct bus_type hv_bus = {
.name = "vmbus",
.match = vmbus_match,
.shutdown = vmbus_shutdown,
.remove = vmbus_remove,
.probe = vmbus_probe,
.uevent = vmbus_uevent,
.dma_configure = vmbus_dma_configure,
.dev_groups = vmbus_dev_groups,
.drv_groups = vmbus_drv_groups,
.bus_groups = vmbus_bus_groups,
.pm = &vmbus_pm,
};
struct onmessage_work_context {
struct work_struct work;
struct {
struct hv_message_header header;
u8 payload[];
} msg;
};
static void vmbus_onmessage_work(struct work_struct *work)
{
struct onmessage_work_context *ctx;
/* Do not process messages if we're in DISCONNECTED state */
if (vmbus_connection.conn_state == DISCONNECTED)
return;
ctx = container_of(work, struct onmessage_work_context,
work);
vmbus_onmessage((struct vmbus_channel_message_header *)
&ctx->msg.payload);
kfree(ctx);
}
void vmbus_on_msg_dpc(unsigned long data)
{
struct hv_per_cpu_context *hv_cpu = (void *)data;
void *page_addr = hv_cpu->synic_message_page;
struct hv_message msg_copy, *msg = (struct hv_message *)page_addr +
VMBUS_MESSAGE_SINT;
struct vmbus_channel_message_header *hdr;
enum vmbus_channel_message_type msgtype;
const struct vmbus_channel_message_table_entry *entry;
struct onmessage_work_context *ctx;
__u8 payload_size;
u32 message_type;
/*
* 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
* it is being used in 'struct vmbus_channel_message_header' definition
* which is supposed to match hypervisor ABI.
*/
BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
/*
* Since the message is in memory shared with the host, an erroneous or
* malicious Hyper-V could modify the message while vmbus_on_msg_dpc()
* or individual message handlers are executing; to prevent this, copy
* the message into private memory.
*/
memcpy(&msg_copy, msg, sizeof(struct hv_message));
message_type = msg_copy.header.message_type;
if (message_type == HVMSG_NONE)
/* no msg */
return;
hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload;
msgtype = hdr->msgtype;
trace_vmbus_on_msg_dpc(hdr);
if (msgtype >= CHANNELMSG_COUNT) {
WARN_ONCE(1, "unknown msgtype=%d\n", msgtype);
goto msg_handled;
}
payload_size = msg_copy.header.payload_size;
if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
WARN_ONCE(1, "payload size is too large (%d)\n", payload_size);
goto msg_handled;
}
entry = &channel_message_table[msgtype];
if (!entry->message_handler)
goto msg_handled;
if (payload_size < entry->min_payload_len) {
WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size);
goto msg_handled;
}
if (entry->handler_type == VMHT_BLOCKING) {
ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC);
if (ctx == NULL)
return;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
memcpy(&ctx->msg, &msg_copy, sizeof(msg->header) + payload_size);
/*
* The host can generate a rescind message while we
* may still be handling the original offer. We deal with
* this condition by relying on the synchronization provided
* by offer_in_progress and by channel_mutex. See also the
* inline comments in vmbus_onoffer_rescind().
*/
switch (msgtype) {
case CHANNELMSG_RESCIND_CHANNELOFFER:
/*
* If we are handling the rescind message;
* schedule the work on the global work queue.
*
* The OFFER message and the RESCIND message should
* not be handled by the same serialized work queue,
* because the OFFER handler may call vmbus_open(),
* which tries to open the channel by sending an
* OPEN_CHANNEL message to the host and waits for
* the host's response; however, if the host has
* rescinded the channel before it receives the
* OPEN_CHANNEL message, the host just silently
* ignores the OPEN_CHANNEL message; as a result,
* the guest's OFFER handler hangs for ever, if we
* handle the RESCIND message in the same serialized
* work queue: the RESCIND handler can not start to
* run before the OFFER handler finishes.
*/
schedule_work(&ctx->work);
break;
case CHANNELMSG_OFFERCHANNEL:
/*
* The host sends the offer message of a given channel
* before sending the rescind message of the same
* channel. These messages are sent to the guest's
* connect CPU; the guest then starts processing them
* in the tasklet handler on this CPU:
*
* VMBUS_CONNECT_CPU
*
* [vmbus_on_msg_dpc()]
* atomic_inc() // CHANNELMSG_OFFERCHANNEL
* queue_work()
* ...
* [vmbus_on_msg_dpc()]
* schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
*
* We rely on the memory-ordering properties of the
* queue_work() and schedule_work() primitives, which
* guarantee that the atomic increment will be visible
* to the CPUs which will execute the offer & rescind
* works by the time these works will start execution.
*/
atomic_inc(&vmbus_connection.offer_in_progress);
fallthrough;
default:
queue_work(vmbus_connection.work_queue, &ctx->work);
}
} else
entry->message_handler(hdr);
msg_handled:
vmbus_signal_eom(msg, message_type);
}
#ifdef CONFIG_PM_SLEEP
/*
* Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
* hibernation, because hv_sock connections can not persist across hibernation.
*/
static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
{
struct onmessage_work_context *ctx;
struct vmbus_channel_rescind_offer *rescind;
WARN_ON(!is_hvsock_channel(channel));
/*
* Allocation size is small and the allocation should really not fail,
* otherwise the state of the hv_sock connections ends up in limbo.
*/
ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
GFP_KERNEL | __GFP_NOFAIL);
/*
* So far, these are not really used by Linux. Just set them to the
* reasonable values conforming to the definitions of the fields.
*/
ctx->msg.header.message_type = 1;
ctx->msg.header.payload_size = sizeof(*rescind);
/* These values are actually used by Linux. */
rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
rescind->child_relid = channel->offermsg.child_relid;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
queue_work(vmbus_connection.work_queue, &ctx->work);
}
#endif /* CONFIG_PM_SLEEP */
/*
* Schedule all channels with events pending
*/
static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
{
unsigned long *recv_int_page;
u32 maxbits, relid;
/*
* The event page can be directly checked to get the id of
* the channel that has the interrupt pending.
*/
void *page_addr = hv_cpu->synic_event_page;
union hv_synic_event_flags *event
= (union hv_synic_event_flags *)page_addr +
VMBUS_MESSAGE_SINT;
maxbits = HV_EVENT_FLAGS_COUNT;
recv_int_page = event->flags;
if (unlikely(!recv_int_page))
return;
for_each_set_bit(relid, recv_int_page, maxbits) {
void (*callback_fn)(void *context);
struct vmbus_channel *channel;
if (!sync_test_and_clear_bit(relid, recv_int_page))
continue;
/* Special case - vmbus channel protocol msg */
if (relid == 0)
continue;
/*
* Pairs with the kfree_rcu() in vmbus_chan_release().
* Guarantees that the channel data structure doesn't
* get freed while the channel pointer below is being
* dereferenced.
*/
rcu_read_lock();
/* Find channel based on relid */
channel = relid2channel(relid);
if (channel == NULL)
goto sched_unlock_rcu;
if (channel->rescind)
goto sched_unlock_rcu;
/*
* Make sure that the ring buffer data structure doesn't get
* freed while we dereference the ring buffer pointer. Test
* for the channel's onchannel_callback being NULL within a
* sched_lock critical section. See also the inline comments
* in vmbus_reset_channel_cb().
*/
spin_lock(&channel->sched_lock);
callback_fn = channel->onchannel_callback;
if (unlikely(callback_fn == NULL))
goto sched_unlock;
trace_vmbus_chan_sched(channel);
++channel->interrupts;
switch (channel->callback_mode) {
case HV_CALL_ISR:
(*callback_fn)(channel->channel_callback_context);
break;
case HV_CALL_BATCHED:
hv_begin_read(&channel->inbound);
fallthrough;
case HV_CALL_DIRECT:
tasklet_schedule(&channel->callback_event);
}
sched_unlock:
spin_unlock(&channel->sched_lock);
sched_unlock_rcu:
rcu_read_unlock();
}
}
static void vmbus_isr(void)
{
struct hv_per_cpu_context *hv_cpu
= this_cpu_ptr(hv_context.cpu_context);
void *page_addr;
struct hv_message *msg;
vmbus_chan_sched(hv_cpu);
page_addr = hv_cpu->synic_message_page;
msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
hv_stimer0_isr();
vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
} else
tasklet_schedule(&hv_cpu->msg_dpc);
}
add_interrupt_randomness(vmbus_interrupt);
}
static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
{
vmbus_isr();
return IRQ_HANDLED;
}
/*
* Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
* buffer and call into Hyper-V to transfer the data.
*/
static void hv_kmsg_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason)
{
struct kmsg_dump_iter iter;
size_t bytes_written;
/* We are only interested in panics. */
if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
return;
/*
* Write dump contents to the page. No need to synchronize; panic should
* be single-threaded.
*/
kmsg_dump_rewind(&iter);
kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE,
&bytes_written);
if (!bytes_written)
return;
/*
* P3 to contain the physical address of the panic page & P4 to
* contain the size of the panic data in that page. Rest of the
* registers are no-op when the NOTIFY_MSG flag is set.
*/
hv_set_register(HV_REGISTER_CRASH_P0, 0);
hv_set_register(HV_REGISTER_CRASH_P1, 0);
hv_set_register(HV_REGISTER_CRASH_P2, 0);
hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page));
hv_set_register(HV_REGISTER_CRASH_P4, bytes_written);
/*
* Let Hyper-V know there is crash data available along with
* the panic message.
*/
hv_set_register(HV_REGISTER_CRASH_CTL,
(HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG));
}
static struct kmsg_dumper hv_kmsg_dumper = {
.dump = hv_kmsg_dump,
};
static void hv_kmsg_dump_register(void)
{
int ret;
hv_panic_page = hv_alloc_hyperv_zeroed_page();
if (!hv_panic_page) {
pr_err("Hyper-V: panic message page memory allocation failed\n");
return;
}
ret = kmsg_dump_register(&hv_kmsg_dumper);
if (ret) {
pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret);
hv_free_hyperv_page((unsigned long)hv_panic_page);
hv_panic_page = NULL;
}
}
static struct ctl_table_header *hv_ctl_table_hdr;
/*
* sysctl option to allow the user to control whether kmsg data should be
* reported to Hyper-V on panic.
*/
static struct ctl_table hv_ctl_table[] = {
{
.procname = "hyperv_record_panic_msg",
.data = &sysctl_record_panic_msg,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE
},
{}
};
static struct ctl_table hv_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = hv_ctl_table
},
{}
};
/*
* vmbus_bus_init -Main vmbus driver initialization routine.
*
* Here, we
* - initialize the vmbus driver context
* - invoke the vmbus hv main init routine
* - retrieve the channel offers
*/
static int vmbus_bus_init(void)
{
int ret;
ret = hv_init();
if (ret != 0) {
pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
return ret;
}
ret = bus_register(&hv_bus);
if (ret)
return ret;
/*
* VMbus interrupts are best modeled as per-cpu interrupts. If
* on an architecture with support for per-cpu IRQs (e.g. ARM64),
* allocate a per-cpu IRQ using standard Linux kernel functionality.
* If not on such an architecture (e.g., x86/x64), then rely on
* code in the arch-specific portion of the code tree to connect
* the VMbus interrupt handler.
*/
if (vmbus_irq == -1) {
hv_setup_vmbus_handler(vmbus_isr);
} else {
vmbus_evt = alloc_percpu(long);
ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr,
"Hyper-V VMbus", vmbus_evt);
if (ret) {
pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d",
vmbus_irq, ret);
free_percpu(vmbus_evt);
goto err_setup;
}
}
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
/*
* Initialize the per-cpu interrupt state and stimer state.
* Then connect to the host.
*/
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
hv_synic_init, hv_synic_cleanup);
if (ret < 0)
goto err_cpuhp;
hyperv_cpuhp_online = ret;
ret = vmbus_connect();
if (ret)
goto err_connect;
if (hv_is_isolation_supported())
sysctl_record_panic_msg = 0;
/*
* Only register if the crash MSRs are available
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
u64 hyperv_crash_ctl;
/*
* Panic message recording (sysctl_record_panic_msg)
* is enabled by default in non-isolated guests and
* disabled by default in isolated guests; the panic
* message recording won't be available in isolated
* guests should the following registration fail.
*/
hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
if (!hv_ctl_table_hdr)
pr_err("Hyper-V: sysctl table register error");
/*
* Register for panic kmsg callback only if the right
* capability is supported by the hypervisor.
*/
hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL);
if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
hv_kmsg_dump_register();
register_die_notifier(&hyperv_die_block);
}
/*
* Always register the panic notifier because we need to unload
* the VMbus channel connection to prevent any VMbus
* activity after the VM panics.
*/
atomic_notifier_chain_register(&panic_notifier_list,
&hyperv_panic_block);
vmbus_request_offers();
return 0;
err_connect:
cpuhp_remove_state(hyperv_cpuhp_online);
err_cpuhp:
hv_synic_free();
err_alloc:
if (vmbus_irq == -1) {
hv_remove_vmbus_handler();
} else {
free_percpu_irq(vmbus_irq, vmbus_evt);
free_percpu(vmbus_evt);
}
err_setup:
bus_unregister(&hv_bus);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
return ret;
}
/**
* __vmbus_child_driver_register() - Register a vmbus's driver
* @hv_driver: Pointer to driver structure you want to register
* @owner: owner module of the drv
* @mod_name: module name string
*
* Registers the given driver with Linux through the 'driver_register()' call
* and sets up the hyper-v vmbus handling for this driver.
* It will return the state of the 'driver_register()' call.
*
*/
int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
{
int ret;
pr_info("registering driver %s\n", hv_driver->name);
ret = vmbus_exists();
if (ret < 0)
return ret;
hv_driver->driver.name = hv_driver->name;
hv_driver->driver.owner = owner;
hv_driver->driver.mod_name = mod_name;
hv_driver->driver.bus = &hv_bus;
spin_lock_init(&hv_driver->dynids.lock);
INIT_LIST_HEAD(&hv_driver->dynids.list);
ret = driver_register(&hv_driver->driver);
return ret;
}
EXPORT_SYMBOL_GPL(__vmbus_driver_register);
/**
* vmbus_driver_unregister() - Unregister a vmbus's driver
* @hv_driver: Pointer to driver structure you want to
* un-register
*
* Un-register the given driver that was previous registered with a call to
* vmbus_driver_register()
*/
void vmbus_driver_unregister(struct hv_driver *hv_driver)
{
pr_info("unregistering driver %s\n", hv_driver->name);
if (!vmbus_exists()) {
driver_unregister(&hv_driver->driver);
vmbus_free_dynids(hv_driver);
}
}
EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
/*
* Called when last reference to channel is gone.
*/
static void vmbus_chan_release(struct kobject *kobj)
{
struct vmbus_channel *channel
= container_of(kobj, struct vmbus_channel, kobj);
kfree_rcu(channel, rcu);
}
struct vmbus_chan_attribute {
struct attribute attr;
ssize_t (*show)(struct vmbus_channel *chan, char *buf);
ssize_t (*store)(struct vmbus_channel *chan,
const char *buf, size_t count);
};
#define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
struct vmbus_chan_attribute chan_attr_##_name \
= __ATTR(_name, _mode, _show, _store)
#define VMBUS_CHAN_ATTR_RW(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
#define VMBUS_CHAN_ATTR_RO(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
#define VMBUS_CHAN_ATTR_WO(_name) \
struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
const struct vmbus_chan_attribute *attribute
= container_of(attr, struct vmbus_chan_attribute, attr);
struct vmbus_channel *chan
= container_of(kobj, struct vmbus_channel, kobj);
if (!attribute->show)
return -EIO;
return attribute->show(chan, buf);
}
static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
struct attribute *attr, const char *buf,
size_t count)
{
const struct vmbus_chan_attribute *attribute
= container_of(attr, struct vmbus_chan_attribute, attr);
struct vmbus_channel *chan
= container_of(kobj, struct vmbus_channel, kobj);
if (!attribute->store)
return -EIO;
return attribute->store(chan, buf, count);
}
static const struct sysfs_ops vmbus_chan_sysfs_ops = {
.show = vmbus_chan_attr_show,
.store = vmbus_chan_attr_store,
};
static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->outbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(out_mask);
static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(in_mask);
static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(read_avail);
static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
{
struct hv_ring_buffer_info *rbi = &channel->outbound;
ssize_t ret;
mutex_lock(&rbi->ring_buffer_mutex);
if (!rbi->ring_buffer) {
mutex_unlock(&rbi->ring_buffer_mutex);
return -EINVAL;
}
ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
mutex_unlock(&rbi->ring_buffer_mutex);
return ret;
}
static VMBUS_CHAN_ATTR_RO(write_avail);
static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%u\n", channel->target_cpu);
}
static ssize_t target_cpu_store(struct vmbus_channel *channel,
const char *buf, size_t count)
{
u32 target_cpu, origin_cpu;
ssize_t ret = count;
if (vmbus_proto_version < VERSION_WIN10_V4_1)
return -EIO;
if (sscanf(buf, "%uu", &target_cpu) != 1)
return -EIO;
/* Validate target_cpu for the cpumask_test_cpu() operation below. */
if (target_cpu >= nr_cpumask_bits)
return -EINVAL;
/* No CPUs should come up or down during this. */
cpus_read_lock();
if (!cpu_online(target_cpu)) {
cpus_read_unlock();
return -EINVAL;
}
/*
* Synchronizes target_cpu_store() and channel closure:
*
* { Initially: state = CHANNEL_OPENED }
*
* CPU1 CPU2
*
* [target_cpu_store()] [vmbus_disconnect_ring()]
*
* LOCK channel_mutex LOCK channel_mutex
* LOAD r1 = state LOAD r2 = state
* IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
* SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
* [...] SEND CLOSECHANNEL
* UNLOCK channel_mutex UNLOCK channel_mutex
*
* Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
* CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
*
* Note. The host processes the channel messages "sequentially", in
* the order in which they are received on a per-partition basis.
*/
mutex_lock(&vmbus_connection.channel_mutex);
/*
* Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
* avoid sending the message and fail here for such channels.
*/
if (channel->state != CHANNEL_OPENED_STATE) {
ret = -EIO;
goto cpu_store_unlock;
}
origin_cpu = channel->target_cpu;
if (target_cpu == origin_cpu)
goto cpu_store_unlock;
if (vmbus_send_modifychannel(channel,
hv_cpu_number_to_vp_number(target_cpu))) {
ret = -EIO;
goto cpu_store_unlock;
}
/*
* For version before VERSION_WIN10_V5_3, the following warning holds:
*
* Warning. At this point, there is *no* guarantee that the host will
* have successfully processed the vmbus_send_modifychannel() request.
* See the header comment of vmbus_send_modifychannel() for more info.
*
* Lags in the processing of the above vmbus_send_modifychannel() can
* result in missed interrupts if the "old" target CPU is taken offline
* before Hyper-V starts sending interrupts to the "new" target CPU.
* But apart from this offlining scenario, the code tolerates such
* lags. It will function correctly even if a channel interrupt comes
* in on a CPU that is different from the channel target_cpu value.
*/
channel->target_cpu = target_cpu;
/* See init_vp_index(). */
if (hv_is_perf_channel(channel))
hv_update_allocated_cpus(origin_cpu, target_cpu);
/* Currently set only for storvsc channels. */
if (channel->change_target_cpu_callback) {
(*channel->change_target_cpu_callback)(channel,
origin_cpu, target_cpu);
}
cpu_store_unlock:
mutex_unlock(&vmbus_connection.channel_mutex);
cpus_read_unlock();
return ret;
}
static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
static ssize_t channel_pending_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%d\n",
channel_pending(channel,
vmbus_connection.monitor_pages[1]));
}
static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL);
static ssize_t channel_latency_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%d\n",
channel_latency(channel,
vmbus_connection.monitor_pages[1]));
}
static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL);
static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%llu\n", channel->interrupts);
}
static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL);
static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
{
return sprintf(buf, "%llu\n", channel->sig_events);
}
static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL);
static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->intr_in_full);
}
static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->intr_out_empty);
}
static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->out_full_first);
}
static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)channel->out_full_total);
}
static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%u\n", channel->offermsg.monitorid);
}
static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL);
static ssize_t subchannel_id_show(struct vmbus_channel *channel,
char *buf)
{
return sprintf(buf, "%u\n",
channel->offermsg.offer.sub_channel_index);
}
static VMBUS_CHAN_ATTR_RO(subchannel_id);
static struct attribute *vmbus_chan_attrs[] = {
&chan_attr_out_mask.attr,
&chan_attr_in_mask.attr,
&chan_attr_read_avail.attr,
&chan_attr_write_avail.attr,
&chan_attr_cpu.attr,
&chan_attr_pending.attr,
&chan_attr_latency.attr,
&chan_attr_interrupts.attr,
&chan_attr_events.attr,
&chan_attr_intr_in_full.attr,
&chan_attr_intr_out_empty.attr,
&chan_attr_out_full_first.attr,
&chan_attr_out_full_total.attr,
&chan_attr_monitor_id.attr,
&chan_attr_subchannel_id.attr,
NULL
};
/*
* Channel-level attribute_group callback function. Returns the permission for
* each attribute, and returns 0 if an attribute is not visible.
*/
static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
const struct vmbus_channel *channel =
container_of(kobj, struct vmbus_channel, kobj);
/* Hide the monitor attributes if the monitor mechanism is not used. */
if (!channel->offermsg.monitor_allocated &&
(attr == &chan_attr_pending.attr ||
attr == &chan_attr_latency.attr ||
attr == &chan_attr_monitor_id.attr))
return 0;
return attr->mode;
}
static struct attribute_group vmbus_chan_group = {
.attrs = vmbus_chan_attrs,
.is_visible = vmbus_chan_attr_is_visible
};
static struct kobj_type vmbus_chan_ktype = {
.sysfs_ops = &vmbus_chan_sysfs_ops,
.release = vmbus_chan_release,
};
/*
* vmbus_add_channel_kobj - setup a sub-directory under device/channels
*/
int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
{
const struct device *device = &dev->device;
struct kobject *kobj = &channel->kobj;
u32 relid = channel->offermsg.child_relid;
int ret;
kobj->kset = dev->channels_kset;
ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
"%u", relid);
if (ret) {
kobject_put(kobj);
return ret;
}
ret = sysfs_create_group(kobj, &vmbus_chan_group);
if (ret) {
/*
* The calling functions' error handling paths will cleanup the
* empty channel directory.
*/
kobject_put(kobj);
dev_err(device, "Unable to set up channel sysfs files\n");
return ret;
}
kobject_uevent(kobj, KOBJ_ADD);
return 0;
}
/*
* vmbus_remove_channel_attr_group - remove the channel's attribute group
*/
void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
{
sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
}
/*
* vmbus_device_create - Creates and registers a new child device
* on the vmbus.
*/
struct hv_device *vmbus_device_create(const guid_t *type,
const guid_t *instance,
struct vmbus_channel *channel)
{
struct hv_device *child_device_obj;
child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
if (!child_device_obj) {
pr_err("Unable to allocate device object for child device\n");
return NULL;
}
child_device_obj->channel = channel;
guid_copy(&child_device_obj->dev_type, type);
guid_copy(&child_device_obj->dev_instance, instance);
child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
return child_device_obj;
}
/*
* vmbus_device_register - Register the child device
*/
int vmbus_device_register(struct hv_device *child_device_obj)
{
struct kobject *kobj = &child_device_obj->device.kobj;
int ret;
dev_set_name(&child_device_obj->device, "%pUl",
&child_device_obj->channel->offermsg.offer.if_instance);
child_device_obj->device.bus = &hv_bus;
child_device_obj->device.parent = &hv_acpi_dev->dev;
child_device_obj->device.release = vmbus_device_release;
child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
/*
* Register with the LDM. This will kick off the driver/device
* binding...which will eventually call vmbus_match() and vmbus_probe()
*/
ret = device_register(&child_device_obj->device);
if (ret) {
pr_err("Unable to register child device\n");
return ret;
}
child_device_obj->channels_kset = kset_create_and_add("channels",
NULL, kobj);
if (!child_device_obj->channels_kset) {
ret = -ENOMEM;
goto err_dev_unregister;
}
ret = vmbus_add_channel_kobj(child_device_obj,
child_device_obj->channel);
if (ret) {
pr_err("Unable to register primary channeln");
goto err_kset_unregister;
}
hv_debug_add_dev_dir(child_device_obj);
return 0;
err_kset_unregister:
kset_unregister(child_device_obj->channels_kset);
err_dev_unregister:
device_unregister(&child_device_obj->device);
return ret;
}
/*
* vmbus_device_unregister - Remove the specified child device
* from the vmbus.
*/
void vmbus_device_unregister(struct hv_device *device_obj)
{
pr_debug("child device %s unregistered\n",
dev_name(&device_obj->device));
kset_unregister(device_obj->channels_kset);
/*
* Kick off the process of unregistering the device.
* This will call vmbus_remove() and eventually vmbus_device_release()
*/
device_unregister(&device_obj->device);
}
/*
* VMBUS is an acpi enumerated device. Get the information we
* need from DSDT.
*/
#define VTPM_BASE_ADDRESS 0xfed40000
static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
{
resource_size_t start = 0;
resource_size_t end = 0;
struct resource *new_res;
struct resource **old_res = &hyperv_mmio;
struct resource **prev_res = NULL;
struct resource r;
switch (res->type) {
/*
* "Address" descriptors are for bus windows. Ignore
* "memory" descriptors, which are for registers on
* devices.
*/
case ACPI_RESOURCE_TYPE_ADDRESS32:
start = res->data.address32.address.minimum;
end = res->data.address32.address.maximum;
break;
case ACPI_RESOURCE_TYPE_ADDRESS64:
start = res->data.address64.address.minimum;
end = res->data.address64.address.maximum;
break;
/*
* The IRQ information is needed only on ARM64, which Hyper-V
* sets up in the extended format. IRQ information is present
* on x86/x64 in the non-extended format but it is not used by
* Linux. So don't bother checking for the non-extended format.
*/
case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
if (!acpi_dev_resource_interrupt(res, 0, &r)) {
pr_err("Unable to parse Hyper-V ACPI interrupt\n");
return AE_ERROR;
}
/* ARM64 INTID for VMbus */
vmbus_interrupt = res->data.extended_irq.interrupts[0];
/* Linux IRQ number */
vmbus_irq = r.start;
return AE_OK;
default:
/* Unused resource type */
return AE_OK;
}
/*
* Ignore ranges that are below 1MB, as they're not
* necessary or useful here.
*/
if (end < 0x100000)
return AE_OK;
new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
if (!new_res)
return AE_NO_MEMORY;
/* If this range overlaps the virtual TPM, truncate it. */
if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
end = VTPM_BASE_ADDRESS;
new_res->name = "hyperv mmio";
new_res->flags = IORESOURCE_MEM;
new_res->start = start;
new_res->end = end;
/*
* If two ranges are adjacent, merge them.
*/
do {
if (!*old_res) {
*old_res = new_res;
break;
}
if (((*old_res)->end + 1) == new_res->start) {
(*old_res)->end = new_res->end;
kfree(new_res);
break;
}
if ((*old_res)->start == new_res->end + 1) {
(*old_res)->start = new_res->start;
kfree(new_res);
break;
}
if ((*old_res)->start > new_res->end) {
new_res->sibling = *old_res;
if (prev_res)
(*prev_res)->sibling = new_res;
*old_res = new_res;
break;
}
prev_res = old_res;
old_res = &(*old_res)->sibling;
} while (1);
return AE_OK;
}
static int vmbus_acpi_remove(struct acpi_device *device)
{
struct resource *cur_res;
struct resource *next_res;
if (hyperv_mmio) {
if (fb_mmio) {
__release_region(hyperv_mmio, fb_mmio->start,
resource_size(fb_mmio));
fb_mmio = NULL;
}
for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
next_res = cur_res->sibling;
kfree(cur_res);
}
}
return 0;
}
static void vmbus_reserve_fb(void)
{
int size;
/*
* Make a claim for the frame buffer in the resource tree under the
* first node, which will be the one below 4GB. The length seems to
* be underreported, particularly in a Generation 1 VM. So start out
* reserving a larger area and make it smaller until it succeeds.
*/
if (screen_info.lfb_base) {
if (efi_enabled(EFI_BOOT))
size = max_t(__u32, screen_info.lfb_size, 0x800000);
else
size = max_t(__u32, screen_info.lfb_size, 0x4000000);
for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
fb_mmio = __request_region(hyperv_mmio,
screen_info.lfb_base, size,
fb_mmio_name, 0);
}
}
}
/**
* vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
* @new: If successful, supplied a pointer to the
* allocated MMIO space.
* @device_obj: Identifies the caller
* @min: Minimum guest physical address of the
* allocation
* @max: Maximum guest physical address
* @size: Size of the range to be allocated
* @align: Alignment of the range to be allocated
* @fb_overlap_ok: Whether this allocation can be allowed
* to overlap the video frame buffer.
*
* This function walks the resources granted to VMBus by the
* _CRS object in the ACPI namespace underneath the parent
* "bridge" whether that's a root PCI bus in the Generation 1
* case or a Module Device in the Generation 2 case. It then
* attempts to allocate from the global MMIO pool in a way that
* matches the constraints supplied in these parameters and by
* that _CRS.
*
* Return: 0 on success, -errno on failure
*/
int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
resource_size_t min, resource_size_t max,
resource_size_t size, resource_size_t align,
bool fb_overlap_ok)
{
struct resource *iter, *shadow;
resource_size_t range_min, range_max, start;
const char *dev_n = dev_name(&device_obj->device);
int retval;
retval = -ENXIO;
mutex_lock(&hyperv_mmio_lock);
/*
* If overlaps with frame buffers are allowed, then first attempt to
* make the allocation from within the reserved region. Because it
* is already reserved, no shadow allocation is necessary.
*/
if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
!(max < fb_mmio->start)) {
range_min = fb_mmio->start;
range_max = fb_mmio->end;
start = (range_min + align - 1) & ~(align - 1);
for (; start + size - 1 <= range_max; start += align) {
*new = request_mem_region_exclusive(start, size, dev_n);
if (*new) {
retval = 0;
goto exit;
}
}
}
for (iter = hyperv_mmio; iter; iter = iter->sibling) {
if ((iter->start >= max) || (iter->end <= min))
continue;
range_min = iter->start;
range_max = iter->end;
start = (range_min + align - 1) & ~(align - 1);
for (; start + size - 1 <= range_max; start += align) {
shadow = __request_region(iter, start, size, NULL,
IORESOURCE_BUSY);
if (!shadow)
continue;
*new = request_mem_region_exclusive(start, size, dev_n);
if (*new) {
shadow->name = (char *)*new;
retval = 0;
goto exit;
}
__release_region(iter, start, size);
}
}
exit:
mutex_unlock(&hyperv_mmio_lock);
return retval;
}
EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
/**
* vmbus_free_mmio() - Free a memory-mapped I/O range.
* @start: Base address of region to release.
* @size: Size of the range to be allocated
*
* This function releases anything requested by
* vmbus_mmio_allocate().
*/
void vmbus_free_mmio(resource_size_t start, resource_size_t size)
{
struct resource *iter;
mutex_lock(&hyperv_mmio_lock);
for (iter = hyperv_mmio; iter; iter = iter->sibling) {
if ((iter->start >= start + size) || (iter->end <= start))
continue;
__release_region(iter, start, size);
}
release_mem_region(start, size);
mutex_unlock(&hyperv_mmio_lock);
}
EXPORT_SYMBOL_GPL(vmbus_free_mmio);
static int vmbus_acpi_add(struct acpi_device *device)
{
acpi_status result;
int ret_val = -ENODEV;
struct acpi_device *ancestor;
hv_acpi_dev = device;
/*
* Older versions of Hyper-V for ARM64 fail to include the _CCA
* method on the top level VMbus device in the DSDT. But devices
* are hardware coherent in all current Hyper-V use cases, so fix
* up the ACPI device to behave as if _CCA is present and indicates
* hardware coherence.
*/
ACPI_COMPANION_SET(&device->dev, device);
if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) &&
device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) {
pr_info("No ACPI _CCA found; assuming coherent device I/O\n");
device->flags.cca_seen = true;
device->flags.coherent_dma = true;
}
result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
vmbus_walk_resources, NULL);
if (ACPI_FAILURE(result))
goto acpi_walk_err;
/*
* Some ancestor of the vmbus acpi device (Gen1 or Gen2
* firmware) is the VMOD that has the mmio ranges. Get that.
*/
for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
vmbus_walk_resources, NULL);
if (ACPI_FAILURE(result))
continue;
if (hyperv_mmio) {
vmbus_reserve_fb();
break;
}
}
ret_val = 0;
acpi_walk_err:
complete(&probe_event);
if (ret_val)
vmbus_acpi_remove(device);
return ret_val;
}
#ifdef CONFIG_PM_SLEEP
static int vmbus_bus_suspend(struct device *dev)
{
struct vmbus_channel *channel, *sc;
while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
/*
* We wait here until the completion of any channel
* offers that are currently in progress.
*/
usleep_range(1000, 2000);
}
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (!is_hvsock_channel(channel))
continue;
vmbus_force_channel_rescinded(channel);
}
mutex_unlock(&vmbus_connection.channel_mutex);
/*
* Wait until all the sub-channels and hv_sock channels have been
* cleaned up. Sub-channels should be destroyed upon suspend, otherwise
* they would conflict with the new sub-channels that will be created
* in the resume path. hv_sock channels should also be destroyed, but
* a hv_sock channel of an established hv_sock connection can not be
* really destroyed since it may still be referenced by the userspace
* application, so we just force the hv_sock channel to be rescinded
* by vmbus_force_channel_rescinded(), and the userspace application
* will thoroughly destroy the channel after hibernation.
*
* Note: the counter nr_chan_close_on_suspend may never go above 0 if
* the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
*/
if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
wait_for_completion(&vmbus_connection.ready_for_suspend_event);
if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
pr_err("Can not suspend due to a previous failed resuming\n");
return -EBUSY;
}
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
/*
* Remove the channel from the array of channels and invalidate
* the channel's relid. Upon resume, vmbus_onoffer() will fix
* up the relid (and other fields, if necessary) and add the
* channel back to the array.
*/
vmbus_channel_unmap_relid(channel);
channel->offermsg.child_relid = INVALID_RELID;
if (is_hvsock_channel(channel)) {
if (!channel->rescind) {
pr_err("hv_sock channel not rescinded!\n");
WARN_ON_ONCE(1);
}
continue;
}
list_for_each_entry(sc, &channel->sc_list, sc_list) {
pr_err("Sub-channel not deleted!\n");
WARN_ON_ONCE(1);
}
atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
}
mutex_unlock(&vmbus_connection.channel_mutex);
vmbus_initiate_unload(false);
/* Reset the event for the next resume. */
reinit_completion(&vmbus_connection.ready_for_resume_event);
return 0;
}
static int vmbus_bus_resume(struct device *dev)
{
struct vmbus_channel_msginfo *msginfo;
size_t msgsize;
int ret;
/*
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
*/
if (!vmbus_proto_version) {
pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
return -EINVAL;
}
msgsize = sizeof(*msginfo) +
sizeof(struct vmbus_channel_initiate_contact);
msginfo = kzalloc(msgsize, GFP_KERNEL);
if (msginfo == NULL)
return -ENOMEM;
ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
kfree(msginfo);
if (ret != 0)
return ret;
WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
vmbus_request_offers();
if (wait_for_completion_timeout(
&vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
pr_err("Some vmbus device is missing after suspending?\n");
/* Reset the event for the next suspend. */
reinit_completion(&vmbus_connection.ready_for_suspend_event);
return 0;
}
#else
#define vmbus_bus_suspend NULL
#define vmbus_bus_resume NULL
#endif /* CONFIG_PM_SLEEP */
static const struct acpi_device_id vmbus_acpi_device_ids[] = {
{"VMBUS", 0},
{"VMBus", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
/*
* Note: we must use the "no_irq" ops, otherwise hibernation can not work with
* PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
* the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
* resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
* dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
* resume callback must also run via the "noirq" ops.
*
* Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
* earlier in this file before vmbus_pm.
*/
static const struct dev_pm_ops vmbus_bus_pm = {
.suspend_noirq = NULL,
.resume_noirq = NULL,
.freeze_noirq = vmbus_bus_suspend,
.thaw_noirq = vmbus_bus_resume,
.poweroff_noirq = vmbus_bus_suspend,
.restore_noirq = vmbus_bus_resume
};
static struct acpi_driver vmbus_acpi_driver = {
.name = "vmbus",
.ids = vmbus_acpi_device_ids,
.ops = {
.add = vmbus_acpi_add,
.remove = vmbus_acpi_remove,
},
.drv.pm = &vmbus_bus_pm,
};
static void hv_kexec_handler(void)
{
hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
mb();
cpuhp_remove_state(hyperv_cpuhp_online);
};
static void hv_crash_handler(struct pt_regs *regs)
{
int cpu;
vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
* doing the cleanup for current CPU only. This should be sufficient
* for kdump.
*/
cpu = smp_processor_id();
hv_stimer_cleanup(cpu);
hv_synic_disable_regs(cpu);
};
static int hv_synic_suspend(void)
{
/*
* When we reach here, all the non-boot CPUs have been offlined.
* If we're in a legacy configuration where stimer Direct Mode is
* not enabled, the stimers on the non-boot CPUs have been unbound
* in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
* hv_stimer_cleanup() -> clockevents_unbind_device().
*
* hv_synic_suspend() only runs on CPU0 with interrupts disabled.
* Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
* 1) it's unnecessary as interrupts remain disabled between
* syscore_suspend() and syscore_resume(): see create_image() and
* resume_target_kernel()
* 2) the stimer on CPU0 is automatically disabled later by
* syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
* -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
* 3) a warning would be triggered if we call
* clockevents_unbind_device(), which may sleep, in an
* interrupts-disabled context.
*/
hv_synic_disable_regs(0);
return 0;
}
static void hv_synic_resume(void)
{
hv_synic_enable_regs(0);
/*
* Note: we don't need to call hv_stimer_init(0), because the timer
* on CPU0 is not unbound in hv_synic_suspend(), and the timer is
* automatically re-enabled in timekeeping_resume().
*/
}
/* The callbacks run only on CPU0, with irqs_disabled. */
static struct syscore_ops hv_synic_syscore_ops = {
.suspend = hv_synic_suspend,
.resume = hv_synic_resume,
};
static int __init hv_acpi_init(void)
{
int ret, t;
if (!hv_is_hyperv_initialized())
return -ENODEV;
if (hv_root_partition)
return 0;
init_completion(&probe_event);
/*
* Get ACPI resources first.
*/
ret = acpi_bus_register_driver(&vmbus_acpi_driver);
if (ret)
return ret;
t = wait_for_completion_timeout(&probe_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto cleanup;
}
/*
* If we're on an architecture with a hardcoded hypervisor
* vector (i.e. x86/x64), override the VMbus interrupt found
* in the ACPI tables. Ensure vmbus_irq is not set since the
* normal Linux IRQ mechanism is not used in this case.
*/
#ifdef HYPERVISOR_CALLBACK_VECTOR
vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR;
vmbus_irq = -1;
#endif
hv_debug_init();
ret = vmbus_bus_init();
if (ret)
goto cleanup;
hv_setup_kexec_handler(hv_kexec_handler);
hv_setup_crash_handler(hv_crash_handler);
register_syscore_ops(&hv_synic_syscore_ops);
return 0;
cleanup:
acpi_bus_unregister_driver(&vmbus_acpi_driver);
hv_acpi_dev = NULL;
return ret;
}
static void __exit vmbus_exit(void)
{
int cpu;
unregister_syscore_ops(&hv_synic_syscore_ops);
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
hv_stimer_global_cleanup();
vmbus_disconnect();
if (vmbus_irq == -1) {
hv_remove_vmbus_handler();
} else {
free_percpu_irq(vmbus_irq, vmbus_evt);
free_percpu(vmbus_evt);
}
for_each_online_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
tasklet_kill(&hv_cpu->msg_dpc);
}
hv_debug_rm_all_dir();
vmbus_free_channels();
kfree(vmbus_connection.channels);
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
kmsg_dump_unregister(&hv_kmsg_dumper);
unregister_die_notifier(&hyperv_die_block);
}
/*
* The panic notifier is always registered, hence we should
* also unconditionally unregister it here as well.
*/
atomic_notifier_chain_unregister(&panic_notifier_list,
&hyperv_panic_block);
free_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
bus_unregister(&hv_bus);
cpuhp_remove_state(hyperv_cpuhp_online);
hv_synic_free();
acpi_bus_unregister_driver(&vmbus_acpi_driver);
}
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
subsys_initcall(hv_acpi_init);
module_exit(vmbus_exit);
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