Research on Virtualization Security in Cloud Computing focuses on securing the virtualized infrastructure that underpins cloud environments, where multiple virtual machines (VMs) and containers share the same physical resources. This area addresses challenges such as hypervisor vulnerabilities, VM isolation breaches, side-channel attacks, and malicious insider threats. Key research directions include designing secure hypervisors with minimal attack surfaces, developing VM introspection and monitoring tools for anomaly detection, and implementing strong isolation techniques to prevent inter-VM attacks. Other emerging topics involve lightweight encryption and access control for virtualized environments, blockchain-enabled trust management, and AI-driven threat detection within virtual layers. Additionally, research on container security, secure VM migration, and hardware-assisted virtualization protection (e.g., Intel VT-x, AMD-V) represents significant avenues for strengthening the resilience, integrity, and trustworthiness of cloud virtualization infrastructures.