vmm: Introduce landlock cmdline parameter

Users can use this cmdline option to enable/disable Landlock based
sandboxing while running cloud-hypervisor.

Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>

src/main.rs

@@ -271,6 +271,17 @@ fn create_app(default_vcpus: String, default_memory: String, default_rng: String
                 .num_args(1..)
                 .group("vm-config"),
         )
+        .arg(
+            Arg::new("landlock")
+                .long("landlock")
+                .num_args(0)
+                .help(
+                    "enable/disable Landlock.",
+                )
+                .action(ArgAction::SetTrue)
+                .default_value("false")
+                .group("vm-config"),
+        )
         .arg(
             Arg::new("net")
                 .long("net")
@@ -1032,6 +1043,7 @@ mod unit_tests {
             platform: None,
             tpm: None,
             preserved_fds: None,
+            landlock_enable: false,
         };
 
         assert_eq!(expected_vm_config, result_vm_config);