Live Virtual Machine Introspection (VMI) enables strong security and management services without trusting the guest OS, but existing frameworks such as LibVMI suffer from high overheads, poor scalability, and weak isolation due to VM pausing and kernel–userspace round-trips. We present GoodKit, a fast and isolated VMI framework. GoodKit colocates observers with the VMM to provide native, pause-free memory access under strict access control without modifying the guest or the hypervisor. To support multiple observers, GoodKit includes a mutualization layer that eliminates redundant introspection and prevents contention on kernel data structures. Across 21 real-world use cases—including rootkit detection, ransomware monitoring, and scheduler introspection—GoodKit consistently delivers high performance, strong isolation, and broad applicability.