Add WSL2 setup tutorial [Docs]

docs/tutorials/Running-urunc-on-wsl2.md

@@ -0,0 +1,98 @@
+# Running `urunc` on WSL2
+
+In this tutorial, we describe how to set up and run `urunc` on
+**Windows Subsystem for Linux 2 (WSL2)** using **QEMU** as the
+underlying hypervisor.
+
+## Prerequisites
+
+Before proceeding, make sure you have a working WSL2 instance with
+Ubuntu installed. You can follow the official
+[Microsoft WSL documentation](https://learn.microsoft.com/en-us/windows/wsl/install)
+to set this up.
+
+### Verify KVM support
+
+`urunc` requires KVM for hardware-accelerated virtualization. On WSL2,
+KVM is available only if nested virtualization is enabled on your
+Windows host.
+
+Verify that `/dev/kvm` exists:
+```bash
+ls -la /dev/kvm
+```
+
+If the device is missing, enable nested virtualization by creating or
+editing the `.wslconfig` file at `%USERPROFILE%\.wslconfig` on your
+Windows host:
+```ini
+[wsl2]
+nestedVirtualization=true
+```
+
+Then restart WSL from PowerShell:
+```powershell
+wsl --shutdown
+```
+
+After restarting, verify KVM is available:
+```bash
+lsmod | grep kvm
+```
+
+You should see `kvm_intel` or `kvm_amd` in the output.
+
+## Install `urunc`
+
+Follow the standard [installation guide](../installation.md) to build
+and install `urunc` and the containerd shim.
+
+## Snapshotter configuration
+
+The default WSL2 kernel does not load the `dm_thin_pool` kernel module,
+which means the `devmapper` snapshotter will not work out of the box.
+
+Verify this by running:
+```bash
+lsmod | grep dm_thin
+```
+
+If the output is empty, you must use the `overlayfs` snapshotter
+instead. This works without any additional configuration on WSL2.
+
+When running containers, use the `--snapshotter overlayfs` flag:
+```bash
+sudo nerdctl run --snapshotter overlayfs --runtime io.containerd.urunc.v2 ...
+```
+
+## Using `nerdctl` instead of Docker
+
+On WSL2, **Docker Desktop** manages its own containerd instance, which
+makes it difficult to register custom runtimes like `urunc`. We
+recommend using standalone `nerdctl` with a manually configured
+containerd instead.
+
+Install `nerdctl` and the required CNI plugins by following the official
+[nerdctl documentation](https://github.com/containerd/nerdctl#install).
+
+Make sure the CNI plugins (`bridge`, `portmap`, etc.) are installed
+under `/opt/cni/bin/`.
+
+## Running a unikernel
+
+Once everything is set up, you can run a unikernel container. For
+example, to run the Unikraft nginx image with QEMU:
+
+```bash
+sudo nerdctl run --rm --snapshotter overlayfs \
+  --runtime io.containerd.urunc.v2 \
+  harbor.nbfc.io/nubificus/urunc/nginx-qemu-unikraft:latest
+```
+
+To verify the unikernel is running, check its IP address from the
+`nerdctl` output and send a request:
+```bash
+curl http://<unikernel-ip>
+```
+
+You should see the default nginx welcome page.

docs/tutorials/index.md

@@ -6,4 +6,5 @@ In this section we include some end-to-end tutorials on deploying
 - [Knative integration](../tutorials/knative)
 - [Non root monitor execution](../tutorials/Non-root-monitor-execution)
 - [Running existing containers over Linux](../tutorials/existing-container-linux)
-- [Running vAccel-enabled Containers with `urunc`](../tutorials/Running-vaccel-with-urunc.md)
+- [Running vAccel-enabled Containers with `urunc`](../tutorials/Running-vaccel-with-urunc.md)
+- [Running `urunc` on WSL2](../tutorials/Running-urunc-on-wsl2.md)