The document discusses virtualization system security testing. It summarizes the work of the 360 Marvel Team, which focuses on attack and defense techniques in virtualized systems. The team has developed a fuzzing framework to test for vulnerabilities in hardware virtualization components like Qemu and Vmware. The framework analyzes data flowing to components, changes it to trigger abnormalities, and records results. Using this framework, the team has found over 20 vulnerabilities. The document outlines the framework's functions, workflow, and how it was used to analyze vulnerabilities in the Qemu e1000 network device and Vmware e1000 network device through a case study.