mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 17:01:14 +00:00
![Haitao Huang](/assets/img/avatar_default.png)
Change 'new_usage' type to u64 so it can be compared with unsigned 'max' and 'capacity' properly even if the value crosses the signed boundary. Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
422 lines
9.6 KiB
C
422 lines
9.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Miscellaneous cgroup controller
|
|
*
|
|
* Copyright 2020 Google LLC
|
|
* Author: Vipin Sharma <vipinsh@google.com>
|
|
*/
|
|
|
|
#include <linux/limits.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/atomic.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/misc_cgroup.h>
|
|
|
|
#define MAX_STR "max"
|
|
#define MAX_NUM U64_MAX
|
|
|
|
/* Miscellaneous res name, keep it in sync with enum misc_res_type */
|
|
static const char *const misc_res_name[] = {
|
|
#ifdef CONFIG_KVM_AMD_SEV
|
|
/* AMD SEV ASIDs resource */
|
|
"sev",
|
|
/* AMD SEV-ES ASIDs resource */
|
|
"sev_es",
|
|
#endif
|
|
};
|
|
|
|
/* Root misc cgroup */
|
|
static struct misc_cg root_cg;
|
|
|
|
/*
|
|
* Miscellaneous resources capacity for the entire machine. 0 capacity means
|
|
* resource is not initialized or not present in the host.
|
|
*
|
|
* root_cg.max and capacity are independent of each other. root_cg.max can be
|
|
* more than the actual capacity. We are using Limits resource distribution
|
|
* model of cgroup for miscellaneous controller.
|
|
*/
|
|
static u64 misc_res_capacity[MISC_CG_RES_TYPES];
|
|
|
|
/**
|
|
* parent_misc() - Get the parent of the passed misc cgroup.
|
|
* @cgroup: cgroup whose parent needs to be fetched.
|
|
*
|
|
* Context: Any context.
|
|
* Return:
|
|
* * struct misc_cg* - Parent of the @cgroup.
|
|
* * %NULL - If @cgroup is null or the passed cgroup does not have a parent.
|
|
*/
|
|
static struct misc_cg *parent_misc(struct misc_cg *cgroup)
|
|
{
|
|
return cgroup ? css_misc(cgroup->css.parent) : NULL;
|
|
}
|
|
|
|
/**
|
|
* valid_type() - Check if @type is valid or not.
|
|
* @type: misc res type.
|
|
*
|
|
* Context: Any context.
|
|
* Return:
|
|
* * true - If valid type.
|
|
* * false - If not valid type.
|
|
*/
|
|
static inline bool valid_type(enum misc_res_type type)
|
|
{
|
|
return type >= 0 && type < MISC_CG_RES_TYPES;
|
|
}
|
|
|
|
/**
|
|
* misc_cg_res_total_usage() - Get the current total usage of the resource.
|
|
* @type: misc res type.
|
|
*
|
|
* Context: Any context.
|
|
* Return: Current total usage of the resource.
|
|
*/
|
|
u64 misc_cg_res_total_usage(enum misc_res_type type)
|
|
{
|
|
if (valid_type(type))
|
|
return atomic64_read(&root_cg.res[type].usage);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(misc_cg_res_total_usage);
|
|
|
|
/**
|
|
* misc_cg_set_capacity() - Set the capacity of the misc cgroup res.
|
|
* @type: Type of the misc res.
|
|
* @capacity: Supported capacity of the misc res on the host.
|
|
*
|
|
* If capacity is 0 then the charging a misc cgroup fails for that type.
|
|
*
|
|
* Context: Any context.
|
|
* Return:
|
|
* * %0 - Successfully registered the capacity.
|
|
* * %-EINVAL - If @type is invalid.
|
|
*/
|
|
int misc_cg_set_capacity(enum misc_res_type type, u64 capacity)
|
|
{
|
|
if (!valid_type(type))
|
|
return -EINVAL;
|
|
|
|
WRITE_ONCE(misc_res_capacity[type], capacity);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(misc_cg_set_capacity);
|
|
|
|
/**
|
|
* misc_cg_cancel_charge() - Cancel the charge from the misc cgroup.
|
|
* @type: Misc res type in misc cg to cancel the charge from.
|
|
* @cg: Misc cgroup to cancel charge from.
|
|
* @amount: Amount to cancel.
|
|
*
|
|
* Context: Any context.
|
|
*/
|
|
static void misc_cg_cancel_charge(enum misc_res_type type, struct misc_cg *cg,
|
|
u64 amount)
|
|
{
|
|
WARN_ONCE(atomic64_add_negative(-amount, &cg->res[type].usage),
|
|
"misc cgroup resource %s became less than 0",
|
|
misc_res_name[type]);
|
|
}
|
|
|
|
/**
|
|
* misc_cg_try_charge() - Try charging the misc cgroup.
|
|
* @type: Misc res type to charge.
|
|
* @cg: Misc cgroup which will be charged.
|
|
* @amount: Amount to charge.
|
|
*
|
|
* Charge @amount to the misc cgroup. Caller must use the same cgroup during
|
|
* the uncharge call.
|
|
*
|
|
* Context: Any context.
|
|
* Return:
|
|
* * %0 - If successfully charged.
|
|
* * -EINVAL - If @type is invalid or misc res has 0 capacity.
|
|
* * -EBUSY - If max limit will be crossed or total usage will be more than the
|
|
* capacity.
|
|
*/
|
|
int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount)
|
|
{
|
|
struct misc_cg *i, *j;
|
|
int ret;
|
|
struct misc_res *res;
|
|
u64 new_usage;
|
|
|
|
if (!(valid_type(type) && cg && READ_ONCE(misc_res_capacity[type])))
|
|
return -EINVAL;
|
|
|
|
if (!amount)
|
|
return 0;
|
|
|
|
for (i = cg; i; i = parent_misc(i)) {
|
|
res = &i->res[type];
|
|
|
|
new_usage = atomic64_add_return(amount, &res->usage);
|
|
if (new_usage > READ_ONCE(res->max) ||
|
|
new_usage > READ_ONCE(misc_res_capacity[type])) {
|
|
ret = -EBUSY;
|
|
goto err_charge;
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
err_charge:
|
|
for (j = i; j; j = parent_misc(j)) {
|
|
atomic64_inc(&j->res[type].events);
|
|
cgroup_file_notify(&j->events_file);
|
|
}
|
|
|
|
for (j = cg; j != i; j = parent_misc(j))
|
|
misc_cg_cancel_charge(type, j, amount);
|
|
misc_cg_cancel_charge(type, i, amount);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(misc_cg_try_charge);
|
|
|
|
/**
|
|
* misc_cg_uncharge() - Uncharge the misc cgroup.
|
|
* @type: Misc res type which was charged.
|
|
* @cg: Misc cgroup which will be uncharged.
|
|
* @amount: Charged amount.
|
|
*
|
|
* Context: Any context.
|
|
*/
|
|
void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg, u64 amount)
|
|
{
|
|
struct misc_cg *i;
|
|
|
|
if (!(amount && valid_type(type) && cg))
|
|
return;
|
|
|
|
for (i = cg; i; i = parent_misc(i))
|
|
misc_cg_cancel_charge(type, i, amount);
|
|
}
|
|
EXPORT_SYMBOL_GPL(misc_cg_uncharge);
|
|
|
|
/**
|
|
* misc_cg_max_show() - Show the misc cgroup max limit.
|
|
* @sf: Interface file
|
|
* @v: Arguments passed
|
|
*
|
|
* Context: Any context.
|
|
* Return: 0 to denote successful print.
|
|
*/
|
|
static int misc_cg_max_show(struct seq_file *sf, void *v)
|
|
{
|
|
int i;
|
|
struct misc_cg *cg = css_misc(seq_css(sf));
|
|
u64 max;
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
if (READ_ONCE(misc_res_capacity[i])) {
|
|
max = READ_ONCE(cg->res[i].max);
|
|
if (max == MAX_NUM)
|
|
seq_printf(sf, "%s max\n", misc_res_name[i]);
|
|
else
|
|
seq_printf(sf, "%s %llu\n", misc_res_name[i],
|
|
max);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* misc_cg_max_write() - Update the maximum limit of the cgroup.
|
|
* @of: Handler for the file.
|
|
* @buf: Data from the user. It should be either "max", 0, or a positive
|
|
* integer.
|
|
* @nbytes: Number of bytes of the data.
|
|
* @off: Offset in the file.
|
|
*
|
|
* User can pass data like:
|
|
* echo sev 23 > misc.max, OR
|
|
* echo sev max > misc.max
|
|
*
|
|
* Context: Any context.
|
|
* Return:
|
|
* * >= 0 - Number of bytes processed in the input.
|
|
* * -EINVAL - If buf is not valid.
|
|
* * -ERANGE - If number is bigger than the u64 capacity.
|
|
*/
|
|
static ssize_t misc_cg_max_write(struct kernfs_open_file *of, char *buf,
|
|
size_t nbytes, loff_t off)
|
|
{
|
|
struct misc_cg *cg;
|
|
u64 max;
|
|
int ret = 0, i;
|
|
enum misc_res_type type = MISC_CG_RES_TYPES;
|
|
char *token;
|
|
|
|
buf = strstrip(buf);
|
|
token = strsep(&buf, " ");
|
|
|
|
if (!token || !buf)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
if (!strcmp(misc_res_name[i], token)) {
|
|
type = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (type == MISC_CG_RES_TYPES)
|
|
return -EINVAL;
|
|
|
|
if (!strcmp(MAX_STR, buf)) {
|
|
max = MAX_NUM;
|
|
} else {
|
|
ret = kstrtou64(buf, 0, &max);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
cg = css_misc(of_css(of));
|
|
|
|
if (READ_ONCE(misc_res_capacity[type]))
|
|
WRITE_ONCE(cg->res[type].max, max);
|
|
else
|
|
ret = -EINVAL;
|
|
|
|
return ret ? ret : nbytes;
|
|
}
|
|
|
|
/**
|
|
* misc_cg_current_show() - Show the current usage of the misc cgroup.
|
|
* @sf: Interface file
|
|
* @v: Arguments passed
|
|
*
|
|
* Context: Any context.
|
|
* Return: 0 to denote successful print.
|
|
*/
|
|
static int misc_cg_current_show(struct seq_file *sf, void *v)
|
|
{
|
|
int i;
|
|
u64 usage;
|
|
struct misc_cg *cg = css_misc(seq_css(sf));
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
usage = atomic64_read(&cg->res[i].usage);
|
|
if (READ_ONCE(misc_res_capacity[i]) || usage)
|
|
seq_printf(sf, "%s %llu\n", misc_res_name[i], usage);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* misc_cg_capacity_show() - Show the total capacity of misc res on the host.
|
|
* @sf: Interface file
|
|
* @v: Arguments passed
|
|
*
|
|
* Only present in the root cgroup directory.
|
|
*
|
|
* Context: Any context.
|
|
* Return: 0 to denote successful print.
|
|
*/
|
|
static int misc_cg_capacity_show(struct seq_file *sf, void *v)
|
|
{
|
|
int i;
|
|
u64 cap;
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
cap = READ_ONCE(misc_res_capacity[i]);
|
|
if (cap)
|
|
seq_printf(sf, "%s %llu\n", misc_res_name[i], cap);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int misc_events_show(struct seq_file *sf, void *v)
|
|
{
|
|
struct misc_cg *cg = css_misc(seq_css(sf));
|
|
u64 events;
|
|
int i;
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
events = atomic64_read(&cg->res[i].events);
|
|
if (READ_ONCE(misc_res_capacity[i]) || events)
|
|
seq_printf(sf, "%s.max %llu\n", misc_res_name[i], events);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Misc cgroup interface files */
|
|
static struct cftype misc_cg_files[] = {
|
|
{
|
|
.name = "max",
|
|
.write = misc_cg_max_write,
|
|
.seq_show = misc_cg_max_show,
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
},
|
|
{
|
|
.name = "current",
|
|
.seq_show = misc_cg_current_show,
|
|
},
|
|
{
|
|
.name = "capacity",
|
|
.seq_show = misc_cg_capacity_show,
|
|
.flags = CFTYPE_ONLY_ON_ROOT,
|
|
},
|
|
{
|
|
.name = "events",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.file_offset = offsetof(struct misc_cg, events_file),
|
|
.seq_show = misc_events_show,
|
|
},
|
|
{}
|
|
};
|
|
|
|
/**
|
|
* misc_cg_alloc() - Allocate misc cgroup.
|
|
* @parent_css: Parent cgroup.
|
|
*
|
|
* Context: Process context.
|
|
* Return:
|
|
* * struct cgroup_subsys_state* - css of the allocated cgroup.
|
|
* * ERR_PTR(-ENOMEM) - No memory available to allocate.
|
|
*/
|
|
static struct cgroup_subsys_state *
|
|
misc_cg_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
enum misc_res_type i;
|
|
struct misc_cg *cg;
|
|
|
|
if (!parent_css) {
|
|
cg = &root_cg;
|
|
} else {
|
|
cg = kzalloc(sizeof(*cg), GFP_KERNEL);
|
|
if (!cg)
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
|
|
WRITE_ONCE(cg->res[i].max, MAX_NUM);
|
|
atomic64_set(&cg->res[i].usage, 0);
|
|
}
|
|
|
|
return &cg->css;
|
|
}
|
|
|
|
/**
|
|
* misc_cg_free() - Free the misc cgroup.
|
|
* @css: cgroup subsys object.
|
|
*
|
|
* Context: Any context.
|
|
*/
|
|
static void misc_cg_free(struct cgroup_subsys_state *css)
|
|
{
|
|
kfree(css_misc(css));
|
|
}
|
|
|
|
/* Cgroup controller callbacks */
|
|
struct cgroup_subsys misc_cgrp_subsys = {
|
|
.css_alloc = misc_cg_alloc,
|
|
.css_free = misc_cg_free,
|
|
.legacy_cftypes = misc_cg_files,
|
|
.dfl_cftypes = misc_cg_files,
|
|
};
|