mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
2060061767
Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(), which makes the code a bit shorter and easier to read. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210526141019.13752-1-yuehaibing@huawei.com Signed-off-by: Juergen Gross <jgross@suse.com>
265 lines
7.1 KiB
C
265 lines
7.1 KiB
C
/******************************************************************************
|
|
* Xen balloon driver - enables returning/claiming memory to/from Xen.
|
|
*
|
|
* Copyright (c) 2003, B Dragovic
|
|
* Copyright (c) 2003-2004, M Williamson, K Fraser
|
|
* Copyright (c) 2005 Dan M. Smith, IBM Corporation
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation; or, when distributed
|
|
* separately from the Linux kernel or incorporated into other
|
|
* software packages, subject to the following license:
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this source file (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use, copy, modify,
|
|
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
|
|
* and to permit persons to whom the Software is furnished to do so, subject to
|
|
* the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/init.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/memory_hotplug.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/interface/xen.h>
|
|
#include <xen/balloon.h>
|
|
#include <xen/xenbus.h>
|
|
#include <xen/features.h>
|
|
#include <xen/page.h>
|
|
#include <xen/mem-reservation.h>
|
|
|
|
#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
|
|
|
|
#define BALLOON_CLASS_NAME "xen_memory"
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
u64 xen_saved_max_mem_size = 0;
|
|
#endif
|
|
|
|
static struct device balloon_dev;
|
|
|
|
static int register_balloon(struct device *dev);
|
|
|
|
/* React to a change in the target key */
|
|
static void watch_target(struct xenbus_watch *watch,
|
|
const char *path, const char *token)
|
|
{
|
|
unsigned long long new_target, static_max;
|
|
int err;
|
|
static bool watch_fired;
|
|
static long target_diff;
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
/* The balloon driver will take care of adding memory now. */
|
|
if (xen_saved_max_mem_size)
|
|
max_mem_size = xen_saved_max_mem_size;
|
|
#endif
|
|
|
|
err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
|
|
if (err != 1) {
|
|
/* This is ok (for domain0 at least) - so just return */
|
|
return;
|
|
}
|
|
|
|
/* The given memory/target value is in KiB, so it needs converting to
|
|
* pages. PAGE_SHIFT converts bytes to pages, hence PAGE_SHIFT - 10.
|
|
*/
|
|
new_target >>= PAGE_SHIFT - 10;
|
|
|
|
if (!watch_fired) {
|
|
watch_fired = true;
|
|
|
|
if ((xenbus_scanf(XBT_NIL, "memory", "static-max",
|
|
"%llu", &static_max) == 1) ||
|
|
(xenbus_scanf(XBT_NIL, "memory", "memory_static_max",
|
|
"%llu", &static_max) == 1))
|
|
static_max >>= PAGE_SHIFT - 10;
|
|
else
|
|
static_max = balloon_stats.current_pages;
|
|
|
|
target_diff = (xen_pv_domain() || xen_initial_domain()) ? 0
|
|
: static_max - balloon_stats.target_pages;
|
|
}
|
|
|
|
balloon_set_new_target(new_target - target_diff);
|
|
}
|
|
static struct xenbus_watch target_watch = {
|
|
.node = "memory/target",
|
|
.callback = watch_target,
|
|
};
|
|
|
|
|
|
static int balloon_init_watcher(struct notifier_block *notifier,
|
|
unsigned long event,
|
|
void *data)
|
|
{
|
|
int err;
|
|
|
|
err = register_xenbus_watch(&target_watch);
|
|
if (err)
|
|
pr_err("Failed to set balloon watcher\n");
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block xenstore_notifier = {
|
|
.notifier_call = balloon_init_watcher,
|
|
};
|
|
|
|
void xen_balloon_init(void)
|
|
{
|
|
register_balloon(&balloon_dev);
|
|
|
|
register_xenstore_notifier(&xenstore_notifier);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_balloon_init);
|
|
|
|
#define BALLOON_SHOW(name, format, args...) \
|
|
static ssize_t name##_show(struct device *dev, \
|
|
struct device_attribute *attr, \
|
|
char *buf) \
|
|
{ \
|
|
return sprintf(buf, format, ##args); \
|
|
} \
|
|
static DEVICE_ATTR_RO(name)
|
|
|
|
BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
|
|
BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
|
|
BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_high));
|
|
|
|
static DEVICE_ULONG_ATTR(schedule_delay, 0444, balloon_stats.schedule_delay);
|
|
static DEVICE_ULONG_ATTR(max_schedule_delay, 0644, balloon_stats.max_schedule_delay);
|
|
static DEVICE_ULONG_ATTR(retry_count, 0444, balloon_stats.retry_count);
|
|
static DEVICE_ULONG_ATTR(max_retry_count, 0644, balloon_stats.max_retry_count);
|
|
static DEVICE_BOOL_ATTR(scrub_pages, 0644, xen_scrub_pages);
|
|
|
|
static ssize_t target_kb_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return sprintf(buf, "%lu\n", PAGES2KB(balloon_stats.target_pages));
|
|
}
|
|
|
|
static ssize_t target_kb_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
char *endchar;
|
|
unsigned long long target_bytes;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
|
|
|
|
balloon_set_new_target(target_bytes >> PAGE_SHIFT);
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(target_kb);
|
|
|
|
static ssize_t target_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return sprintf(buf, "%llu\n",
|
|
(unsigned long long)balloon_stats.target_pages
|
|
<< PAGE_SHIFT);
|
|
}
|
|
|
|
static ssize_t target_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
char *endchar;
|
|
unsigned long long target_bytes;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
target_bytes = memparse(buf, &endchar);
|
|
|
|
balloon_set_new_target(target_bytes >> PAGE_SHIFT);
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(target);
|
|
|
|
static struct attribute *balloon_attrs[] = {
|
|
&dev_attr_target_kb.attr,
|
|
&dev_attr_target.attr,
|
|
&dev_attr_schedule_delay.attr.attr,
|
|
&dev_attr_max_schedule_delay.attr.attr,
|
|
&dev_attr_retry_count.attr.attr,
|
|
&dev_attr_max_retry_count.attr.attr,
|
|
&dev_attr_scrub_pages.attr.attr,
|
|
NULL
|
|
};
|
|
|
|
static const struct attribute_group balloon_group = {
|
|
.attrs = balloon_attrs
|
|
};
|
|
|
|
static struct attribute *balloon_info_attrs[] = {
|
|
&dev_attr_current_kb.attr,
|
|
&dev_attr_low_kb.attr,
|
|
&dev_attr_high_kb.attr,
|
|
NULL
|
|
};
|
|
|
|
static const struct attribute_group balloon_info_group = {
|
|
.name = "info",
|
|
.attrs = balloon_info_attrs
|
|
};
|
|
|
|
static const struct attribute_group *balloon_groups[] = {
|
|
&balloon_group,
|
|
&balloon_info_group,
|
|
NULL
|
|
};
|
|
|
|
static struct bus_type balloon_subsys = {
|
|
.name = BALLOON_CLASS_NAME,
|
|
.dev_name = BALLOON_CLASS_NAME,
|
|
};
|
|
|
|
static int register_balloon(struct device *dev)
|
|
{
|
|
int error;
|
|
|
|
error = subsys_system_register(&balloon_subsys, NULL);
|
|
if (error)
|
|
return error;
|
|
|
|
dev->id = 0;
|
|
dev->bus = &balloon_subsys;
|
|
dev->groups = balloon_groups;
|
|
|
|
error = device_register(dev);
|
|
if (error) {
|
|
bus_unregister(&balloon_subsys);
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|