---
title: "Why /dev/kvm loses its permission on WSL2"
description: "Each new VM makes udev rewrite the device's ACL for the active seat, and WSL has no seat, so a setfacl entry is gone after the first VM. Membership in the kvm group lasts."
url: "https://mko.run/notes/2026-10-27-wsl2-kvm/"
language: "en"
published: 2026-10-27
tags: ["wsl2", "kvm", "upstream"]
---
# Why /dev/kvm loses its permission on WSL2

Each new VM makes udev rewrite the device's ACL for the active seat, and WSL has no seat, so a `setfacl` entry is gone after the first VM. Membership in the `kvm` group lasts.