wsl2: cover custom WSL2 kernels

Author: Andrea Reale

content/manuals/desktop/features/wsl/_index.md

@@ -109,3 +109,4 @@ Docker Desktop does not require any particular Linux distributions to be install
 - [Explore best practices](best-practices.md)
 - [Understand how to develop with Docker and WSL 2](use-wsl.md)
 - [Learn about GPU support with WSL 2](/manuals/desktop/features/gpu.md)
+- [Custom kernels on WSL](custom-kernels.md)

content/manuals/desktop/features/wsl/custom-kernels.md

@@ -0,0 +1,34 @@
+---
+title: Custom kernels on WSL 
+description: Using custom kernels with Docker Desktop on WSL 2
+keywords: wsl, docker desktop, custom kernel
+tags: [Best practices, troubleshooting]
+aliases:
+- /desktop/wsl/custom-kernels/
+---
+
+Docker Desktop depends on several kernel features built into the default
+WSL 2 Linux kernel distributed by Microsoft. Because of that, **using a
+custom kernel with Docker Desktop on WSL 2 is not officially supported**
+and may cause issues with Docker Desktop startup or operation.
+
+At the same time, we understand that in some cases it may be necessary
+to run custom kernels; Docker Desktop does not block their use, and
+some users have reported success using them.
+
+If you choose to use a custom kernel, we suggest starting
+from the kernel tree distributed by Microsoft at their [official
+repository](https://github.com/microsoft/WSL2-Linux-Kernel) and adding
+the features you need on top of that.
+
+We suggest to:
+- Use the same kernel version as the one distributed by the latest WSL2
+release (you can find the version by running `wsl.exe --system uname -r`
+in a terminal).
+- Start from the default kernel configuration as provided by Microsoft
+in their [repository](https://github.com/microsoft/WSL2-Linux-Kernel)
+and add the features you need on top of that.
+- Make sure that your kernel build environment includes `pahole` and
+its version is properly reflected in the corresponding kernel config
+(`CONFIG_PAHOLE_VERSION`).
+