cgroup/misc: Change counters to be explicit 64bit types

So the variables can account for resources of huge quantities even on
32-bit machines.

Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

cgroup/misc: update struct members descriptions

Update the miscellaneous controller's structure member's description of
struct misc_res and struct misc_cg.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

misc_cgroup: remove error log to avoid log flood

In scenarios where containers are frequently created and deleted,
a large number of error logs maybe generated. The logs only show
which node is about to go over the max limit, not the node which
resource request failed. As misc.events has provided relevant
information, maybe we can remove this log.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

misc_cgroup: introduce misc.events to count failures

Introduce misc.events to make it easier for us to understand
the pressure of resources. Currently only the 'max' event is
implemented, which indicates the times the resource is about
to exceeds the max limit.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

cgroup: misc: mark dummy misc_cg_res_total_usage() static inline

The dummy implementation was missing static inline triggering the following
compile warning on llvm.

In file included from arch/x86/kvm/svm/sev.c:17:
>> include/linux/misc_cgroup.h:98:15: warning: no previous prototype for function 'misc_cg_res_total_usage' [-Wmissing-prototypes]
unsigned long misc_cg_res_total_usage(enum misc_res_type type)
^
include/linux/misc_cgroup.h:98:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
unsigned long misc_cg_res_total_usage(enum misc_res_type type)
^
static
1 warning generated.

Add it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>

svm/sev: Register SEV and SEV-ES ASIDs to the misc controller

Secure Encrypted Virtualization (SEV) and Secure Encrypted
Virtualization - Encrypted State (SEV-ES) ASIDs are used to encrypt KVMs
on AMD platform. These ASIDs are available in the limited quantities on
a host.

Register their capacity and usage to the misc controller for tracking
via cgroups.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

cgroup: Add misc cgroup controller

The Miscellaneous cgroup provides the resource limiting and tracking
mechanism for the scalar resources which cannot be abstracted like the
other cgroup resources. Controller is enabled by the CONFIG_CGROUP_MISC
config option.

A resource can be added to the controller via enum misc_res_type{} in
the include/linux/misc_cgroup.h file and the corresponding name via
misc_res_name[] in the kernel/cgroup/misc.c file. Provider of the
resource must set its capacity prior to using the resource by calling
misc_cg_set_capacity().

Once a capacity is set then the resource usage can be updated using
charge and uncharge APIs. All of the APIs to interact with misc
controller are in include/linux/misc_cgroup.h.

Miscellaneous controller provides 3 interface files. If two misc
resources (res_a and res_b) are registered then:

misc.capacity
A read-only flat-keyed file shown only in the root cgroup. It shows
miscellaneous scalar resources available on the platform along with
their quantities::

$ cat misc.capacity
res_a 50
res_b 10

misc.current
A read-only flat-keyed file shown in the non-root cgroups. It shows
the current usage of the resources in the cgroup and its children::

$ cat misc.current
res_a 3
res_b 0

misc.max
A read-write flat-keyed file shown in the non root cgroups. Allowed
maximum usage of the resources in the cgroup and its children.::

$ cat misc.max
res_a max
res_b 4

Limit can be set by::

# echo res_a 1 > misc.max

Limit can be set to max by::

# echo res_a max > misc.max

Limits can be set more than the capacity value in the misc.capacity
file.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>