vm-check

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Checks whether the current system is running inside a virtual machine, using a weighted set of heuristics (CPU flags, systemd-detect-virt, MAC address and disk model signatures, DMI/BIOS vendor strings, kernel modules and guest tools). Available as a command-line tool and as a cross-platform desktop GUI, on both Linux and Windows.

Project layout

This is a Cargo workspace:

• vm-check-core: the detection engine (a library). All platform-specific checks and the confidence-scoring logic live here.
• vm-check-cli: the command-line interface (binary vm-check).
• vm-check-gui: the desktop GUI (binary vm-check-gui), built with egui.

Installation

Dependencies

• A Rust toolchain. That's all you need to build vm-check-cli.

• Building vm-check-gui on Linux additionally needs some system development packages for the windowing/GUI stack. On Debian/Ubuntu:

  sudo apt install libgtk-3-dev libxkbcommon-dev libxcb-shape0-dev libxcb-xfixes0-dev libxcb-render0-dev

  These are only needed to build the GUI; the resulting binary doesn't need libgtk at runtime, just a running X11 or Wayland session.

• Building on Windows needs no extra system packages beyond the Rust toolchain (the MSVC or GNU x86_64-pc-windows target, whichever rustup installed): cargo build handles the rest.

• Cross-compiling for Windows from Linux (--target x86_64-pc-windows-gnu) additionally needs the MinGW-w64 linker. On Debian/Ubuntu:

  sudo apt install gcc-mingw-w64-x86-64
  rustup target add x86_64-pc-windows-gnu

Building from source

cargo build --release --workspace

Binaries are produced at target/release/vm-check (CLI) and target/release/vm-check-gui (GUI); on Windows these are vm-check.exe and vm-check-gui.exe.

Pre-built binaries

Each release has ready-to-run archives attached: vm-check-linux-x86_64.tar.gz and vm-check-windows-x86_64.zip. Extract and run: no installer, nothing to register with the system.

Usage

CLI

vm-check                # run all checks, prompting once if elevated checks are needed
vm-check --no-elevate    # skip checks that need root/sudo (dmesg, dmidecode) entirely
vm-check -y              # don't prompt, run elevated checks automatically
vm-check --json          # machine-readable output for scripting/CI
vm-check -v              # show extra detail (matched strings, skip reasons) per check

Exit codes: 0 likely physical, 1 likely a virtual machine, 2 uncertain, 3 internal error.

On Windows, run it the same way from cmd.exe or PowerShell:

.\vm-check.exe
.\vm-check.exe --json

GUI

Run vm-check-gui and click "Run checks". On Windows, double-click vm-check-gui.exe (no console window is needed) or launch it from PowerShell/cmd.exe.

Elevated / administrator privileges

Only two checks need elevated privileges, and only on Linux: dmesg (reading the kernel ring buffer) and dmidecode (which falls back to sudo only if the unprivileged DMI sysfs read fails). Every other check, including all Windows checks (WMI queries, HKLM registry reads), runs fine as a normal user; Windows never needs Administrator / UAC elevation for any check.

• CLI, Linux: if any privileged checks apply, vm-check asks once ("N check(s) need elevated privileges, run them? [Y/n]") and shells out to sudo only for those specific checks. Use -y/--yes to skip the prompt and proceed, or --no-elevate to skip those checks entirely (no sudo invocation at all).
• GUI, Linux: privileged checks are opt-in via a checkbox in the window. Since a windowed app can't sensibly show an interactive terminal sudo prompt, the practical way to include them is to relaunch the whole GUI as root, e.g. sudo vm-check-gui, and then tick the checkbox.

Testing

cargo test --workspace

This runs:

• vm-check-core: unit tests for every detection heuristic (including the German translations) against a mocked evidence source (MockLinuxEvidence/MockWindowsEvidence), so no real host/VM state is needed, plus tests for SystemEvidence's real file/subprocess I/O against the actual machine running the tests.
• vm-check-cli: unit tests for argument-independent logic (confirm_elevation, output formatting, exit codes), and integration tests in vm-check-cli/tests/cli.rs that spawn the compiled vm-check binary, since main() calls std::process::exit and can't be exercised in-process.
• vm-check-gui: unit tests for the background check-running logic and the language/theme/persistence logic (i18n.rs, App::from_storage/save against a mocked eframe::Storage), plus UI tests that drive App's rendering through egui's own in-memory Context::run, which performs a full immediate-mode layout pass without a display or GPU.

CI (.github/workflows/ci.yml) runs this test suite plus cargo fmt --check and cargo clippy -D warnings on every push, on both Linux and Windows.

Coverage

cargo install cargo-llvm-cov
rustup component add llvm-tools-preview
cargo llvm-cov --workspace --summary-only

Screenshots

CLI

Physical Linux host, every check passes:

Windows VM guest, every check fails:

GUI

Light theme, physical Linux host	Dark theme, same host	Windows VM guest