specs: linux: add intel_rdt cgroup support in specs

Add support for the intel_rdt cgroup resource in Linux-specific
runtime configuration to support runtime.json.

The intel_rdt cgroup subsystem will be available in Linux 4.6 (or later).

Signed-off-by: Xiaochen Shen <[email protected]>

runtime-config-linux.md

@@ -141,7 +141,7 @@ The following parameters can be specified:
 ## Control groups
 
 Also known as cgroups, they are used to restrict resource usage for a container and handle device access.
-cgroups provide controls to restrict cpu, memory, IO, pids and network for the container.
+cgroups provide controls to restrict cpu, memory, IO, pids, network and intel_rdt for the container.
 For more information, see the [kernel cgroups documentation](https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt).
 
 The path to the cgroups can be specified in the Spec via `cgroupsPath`.

runtime_config_linux.go

@@ -196,6 +196,12 @@ type Network struct {
 	Priorities []InterfacePriority `json:"priorities"`
 }
 
+// IntelRdt for Linux cgroup 'intel_rdt' resource management
+type IntelRdt struct {
+	// L3 cache allocation CBM (cache bit mask) for container
+	L3Cbm uint64 `json:"l3Cbm"`
+}
+
 // Resources has container runtime resource constraints
 type Resources struct {
 	// DisableOOMKiller disables the OOM killer for out of memory conditions
@@ -214,6 +220,8 @@ type Resources struct {
 	HugepageLimits []HugepageLimit `json:"hugepageLimits"`
 	// Network restriction configuration
 	Network Network `json:"network"`
+	// IntelRdt restriction configuration
+	IntelRdt IntelRdt `json:"intelRdt"`
 }
 
 // Device represents the information on a Linux special device file