Hyperlight is a production-grade library for safely executing untrusted code inside hypervisor-isolated micro virtual machines. It spins up lightweight VMs in milliseconds without requiring a guest kernel or operating system, making it suitable for sandboxing plugins, serverless functions, and other untrusted workloads. The system supports multiple hypervisor backends (KVM on Linux, MSHV on Windows, WHP on Windows, HVF on macOS) and architectures (x86_64, aarch64), with guest binaries compiled as no_std Rust or C ELF files using a custom libc (picolibc). Communication between host and guest is performed via typed function calls serialized with FlatBuffers over VM exits, and the library provides snapshot/restore capabilities using an OCI-compatible image layout for state persistence. The architecture is centered around a host-side Rust library (`hyperlight_host`) that exposes a builder pattern (`SandboxBuilder`) to configure and create sandboxes. The guest runtime (`hyperlight_guest_bin`) handles initialization, page tables, exception handling, and function dispatch. A component model integration (`hyperlight_component_util`) generates Rust bindings from WIT (WebAssembly Interface Types) for higher-level interfaces. The system also includes guest tracing with OpenTelemetry, metrics collection, crash dump generation, and GDB debugging support. External dependencies include hypervisor-specific APIs (KVM ioctls, WHP, HVF), the FlatBuffers serialization library, and the OCI image layout specification for snapshot storage. Key data flows involve the host loading a guest binary, setting up memory regions (code, heap, stack, scratch), registering host functions, and then executing guest functions via VM entries. The guest can call back into the host through registered host functions. Snapshots capture the full guest state (memory, registers, MSRs) and can be saved to disk as OCI-compatible blobs, then restored to create new sandboxes or recover from failures. The library is extensively tested with unit tests, integration tests, fuzz targets, and concurrency stress tests, and is maintained as a CNCF sandbox project with active development and frequent releases.
Multipass is a production-grade virtual machine orchestration tool that provides a daemon (multipassd) with a gRPC API and multiple clients (CLI, Flutter GUI). The daemon manages the full VM lifecycle—launch, start, stop, suspend, snapshot, clone, delete—across several hypervisor backends: QEMU/KVM (Linux/macOS), Apple VZ (macOS), Hyper‑V/HCS (Windows), and VirtualBox (legacy). The codebase demonstrates a client–server architecture where the CLI binary dispatches commands to the daemon via gRPC using protobuf messages, and output is formatted in table/JSON/CSV/YAML. All VMs are provisioned with cloud‑init, and images are fetched from Ubuntu's SimpleStreams or custom HTTP sources with caching and hash verification. Network bridges, DNSMasq on Linux, and HCN/HCS on Windows provide connectivity; mounts are handled via SSHFS (or SMB on Windows). The design includes a plugin‑style backtracking for hypervisors, a persistent settings system backed by QSettings and JSON files, an extensible logging framework (journald, syslog, Windows Event Log), and a new‑release monitor that polls GitHub releases. The repository also contains a Rust component for petname generation and logging, a Python distro‑scraper that periodically refreshes cloud image metadata, and a comprehensive test suite with C++ unit tests (Google Test/Mock) and Python integration tests (pytest, pexpect). Overall, it is a mature, cross‑platform application with strong engineering practices but carries some technical debt from legacy backends and ongoing migrations.
NanaBox is a virtual machine management tool for Windows, built using C++ and the Windows API. It utilizes the Windows.UI.Xaml namespace for creating the user interface and has a modular design with separate classes for different features. The application is actively maintained with recent commits and updates.
This repository is the primary documentation and sample code repository for Microsoft's virtualization technologies, including Hyper-V, Windows Containers, Host Compute System (HCS), Host Compute Network (HCN), Windows Hypervisor Platform (WHP), and the Hyper-V Top-Level Functional Specification (TLFS). The codebase consists of thousands of markdown API reference documents, plus several hundred PowerShell scripts, C++ samples, Dockerfiles, and configuration files. The scripts range from production-quality modules (e.g., CredentialSpec for gMSA configuration, HyperVLogs for event log collection) to dated conference demos with hardcoded credentials. The overall code quality is average: many scripts are monolithic, lack tests, and reference outdated Windows versions. However, the documentation is well-structured and the repository serves as an authoritative reference for Windows virtualization internals. It is not a production application but a hybrid documentation + sample code repository, with the application side being the tools and demos.