Worked on the oxidecomputer/propolis repository to address a critical virtualization issue affecting Linux guest boot stability. Focused on kernel development and system programming using Rust, the work involved correcting Intel SMT cache topology reporting by updating CPUID leaf 4 handling. This change ensured that L1 and L2 caches are accurately reported as shared among SMT siblings, aligning with CPUID specifications and resolving persistent boot failures in virtualized environments. Additional improvements included enhancing test coverage for SMT-aware topology and introducing a helper for SMT detection, which streamlined code maintenance and reduced mean time to recovery for topology-related virtualization issues.