Explore a groundbreaking conference talk on virtual machine extrospection presented at LISA15. Delve into the innovative Hyperprobe framework, which enables users to detect the host OS kernel version from within a guest OS in virtualized environments. Learn about the challenges of reverse information retrieval in virtualization and how the researchers analyzed seven years of Linux KVM development to identify detectable features and bugs. Discover the effectiveness of Hyperprobe through its implementation and evaluation in five real-world cloud environments and a controlled testbed. Gain insights into this novel approach that addresses an open problem in virtualization technology, potentially impacting cloud security and management.