Nested virtualization provides strong isolation but pays a non-trivial cost dominated by world switches between the bare-metal and nested layers; prior fixes are either intrusive or give up control over the nested VMs. HyperTurtle offloads selected critical-path parts of the nested hypervisor by encapsulating them as eBPF programs that run safely in the bare-metal hypervisor context, cutting world switches while retaining control and avoiding intrusive changes. Applied to memory management, networking, and profiling, it delivers gains such as 5× faster EPT fault handling and up to 27% faster Kata-container boot.

Received a Best Paper Award at USENIX ATC 2025.