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>
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>
