config-linux: add an initial spec of RDMA related field

This commit adds an initial spec of RDMA related field for Linux
configuration. They will be used for controlling rdmacg of the Linux
kernel.

Signed-off-by: Hitoshi Mitake <[email protected]>

Author: mitake

config-linux.md

@@ -637,6 +637,29 @@ The following parameters can be specified to set up seccomp:
     "mountLabel": "system_u:object_r:svirt_sandbox_file_t:s0:c715,c811"
 ```
 
+### <a name="configLinuxRdmaLimits" />RDMA resource limits
+
+**`rdma_limits`** (array of objects, OPTIONAL) limits resources for network interfaces which support RDMA (e.g. HCA handles).
+For more information, see the [the kernel RMDA controller documentation][cgroup-v1-rdma].
+
+Each entry has the following structure:
+
+* **`interface_name`** (string, REQUIRED) - A name of an interface.
+* **`hca_handle_limit`** (int64, REQUIRED) - Maximum number of HCA Handles (use `-1` to request the maximum available).
+* **`hca_object_limit`** (int64, REQUIRED) - Maximum number of HCA Objects (use `-1` to request the maximum available).
+
+#### Example
+
+```json
+    "rdma_limits": [
+        {
+            "interface_name": "mlx5_0",
+            "hca_handle_limit": 1,
+	    "hca_object_limit": 20
+        }
+   ]
+```
+
 
 [cgroup-v1]: https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt
 [cgroup-v1-blkio]: https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt
@@ -647,6 +670,7 @@ The following parameters can be specified to set up seccomp:
 [cgroup-v1-net-cls]: https://www.kernel.org/doc/Documentation/cgroup-v1/net_cls.txt
 [cgroup-v1-net-prio]: https://www.kernel.org/doc/Documentation/cgroup-v1/net_prio.txt
 [cgroup-v1-pids]: https://www.kernel.org/doc/Documentation/cgroup-v1/pids.txt
+[cgroup-v1-rdma]: https://www.kernel.org/doc/Documentation/cgroup-v1/rdma.txt
 [cgroup-v2]: https://www.kernel.org/doc/Documentation/cgroup-v2.txt
 [devices]: https://www.kernel.org/doc/Documentation/admin-guide/devices.txt
 [devpts]: https://www.kernel.org/doc/Documentation/filesystems/devpts.txt