runtime-rs: Add basic CH implementation

Add a basic runtime-rs `Hypervisor` trait implementation for Cloud
Hypervisor (CH).

> **Notes:**
>
> - This only supports a default Kata configuration for CH currently.
>
> - Since this feature is still under development, `cargo` features have
>   been added to enable the feature optionally. The default is to not enable
>   currently since the code is not ready for general use.
>
>   To enable the feature for testing and development, enable the
>   `cloud-hypervisor` feature in the `virt_container` crate and enable the
>   `cloud-hypervisor` feature for its `hypervisor` dependency.

Fixes: #5242.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

src/runtime-rs/crates/runtimes/virt_container/Cargo.toml

@@ -35,3 +35,9 @@ oci = { path = "../../../../libs/oci" }
 persist = { path = "../../persist"}
 resource = { path = "../../resource" }
 
+[features]
+default = []
+
+# Feature is not yet complete, so not enabled by default.
+# See https://github.com/kata-containers/kata-containers/issues/6264.
+cloud-hypervisor = []

src/runtime-rs/crates/runtimes/virt_container/src/lib.rs

@@ -25,6 +25,12 @@ use hypervisor::{qemu::Qemu, HYPERVISOR_QEMU};
 use kata_types::config::{
     hypervisor::register_hypervisor_plugin, DragonballConfig, QemuConfig, TomlConfig,
 };
+
+#[cfg(feature = "cloud-hypervisor")]
+use hypervisor::ch::CloudHypervisor;
+#[cfg(feature = "cloud-hypervisor")]
+use kata_types::config::{hypervisor::HYPERVISOR_NAME_CH, CloudHypervisorConfig};
+
 use resource::ResourceManager;
 use sandbox::VIRTCONTAINER;
 use tokio::sync::mpsc::Sender;
@@ -39,8 +45,16 @@ impl RuntimeHandler for VirtContainer {
         // register
         let dragonball_config = Arc::new(DragonballConfig::new());
         register_hypervisor_plugin("dragonball", dragonball_config);
+
         let qemu_config = Arc::new(QemuConfig::new());
         register_hypervisor_plugin("qemu", qemu_config);
+
+        #[cfg(feature = "cloud-hypervisor")]
+        {
+            let ch_config = Arc::new(CloudHypervisorConfig::new());
+            register_hypervisor_plugin(HYPERVISOR_NAME_CH, ch_config);
+        }
+
         Ok(())
     }
 
@@ -118,6 +132,17 @@ async fn new_hypervisor(toml_config: &TomlConfig) -> Result<Arc<dyn Hypervisor>>
                 .await;
             Ok(Arc::new(hypervisor))
         }
+
+        #[cfg(feature = "cloud-hypervisor")]
+        HYPERVISOR_NAME_CH => {
+            let mut hypervisor = CloudHypervisor::new();
+
+            hypervisor
+                .set_hypervisor_config(hypervisor_config.clone())
+                .await;
+
+            Ok(Arc::new(hypervisor))
+        }
         _ => Err(anyhow!("Unsupported hypervisor {}", &hypervisor_name)),
     }
 }