gVisor vs systemd-nspawn

gVisor is a free, open-source Linux-compatible sandbox and application kernel for running containers while isolating the host from untrusted code. It is intended for workloads such as user-uploaded, LLM-generated, and third-party code. Instead of passing sandboxed applications’ system calls directly to the host, its Sentry handles them; a Gofer process mediates filesystem access. The project describes a least-privilege design with a restrictive system call filter. It documents use with Docker, Kubernetes, containerd, and OCI runtimes, including Kubernetes configurations using GKE Sandbox, Minikube, or containerd with the gVisor shim. gVisor can stream application trace points to an external threat detection engine such as Falco, and can checkpoint and restore containers. Most CUDA applications can run unmodified in the sandbox with selected NVIDIA driver versions, but GPU support is restricted to certain models, drivers, capabilities, device files, ioctl calls, and platforms. Installation requires Linux 5.6 or later on x86_64 or ARM64. Compatibility is best-effort, and some applications may not work because not every system call, /proc file, or /sys file is implemented. Hardware side-channel protection is generally not provided.

systemd-nspawn has no write-up on Specifiction yet; its figures are above.