tests: Add CPU affinity test for confidential VMs

Add test_cpu_affinity to the common_cvm integration test module
to verify that CPU pinning works correctly in confidential
guest environments.

The test creates a 2-vCPU Ubuntu Jammy-based confidential VM
using GuestFactory and delegates to the existing
_test_cpu_affinity helper to validate vCPU-to-core affinity.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

cloud-hypervisor/tests/integration.rs

@@ -14957,4 +14957,13 @@ mod common_cvm {
             GuestFactory::new_confidential_guest_factory().create_guest(Box::new(disk_config));
         _test_multi_cpu(&guest);
     }
+
+    #[test]
+    fn test_cpu_affinity() {
+        let disk_config = UbuntuDiskConfig::new(JAMMY_IMAGE_NAME.to_string());
+        let guest = GuestFactory::new_confidential_guest_factory()
+            .create_guest(Box::new(disk_config))
+            .with_cpu(2);
+        _test_cpu_affinity(&guest);
+    }
 }