Merge pull request #5341 from jandubois/docs-plain-windows-wsl2

docs: document the Windows host SSH toolchain

website/content/en/docs/config/environment-variables.md

@@ -214,3 +214,27 @@ This page documents the environment variables used in Lima.
   ```sh
   export QEMU_SYSTEM_X86_64=/usr/local/bin/qemu-system-x86_64
   ```
+
+### `SSH`
+
+- **Description**: Command to run in place of the `ssh` executable. The value is
+  split into shell tokens, so it can include arguments as well as a path.
+  `limactl copy` passes none of the `SSH` arguments to `scp`. It finds `scp`
+  on `$PATH`, except on Windows, where it takes the `scp.exe` next to the
+  selected `ssh.exe`. Tokenization reads `\` as an escape and splits on
+  spaces, so a Windows path works only inside single quotes; unquoted,
+  `C:\Program Files\Git\usr\bin\ssh.exe` arrives as `C:Program`.
+- **Default**: unset. Lima then searches `$PATH`; on Windows it takes the first
+  directory holding `ssh.exe`, `scp.exe`, and `ssh-keygen.exe` together, and
+  falls back to `%SystemRoot%\System32\OpenSSH`.
+- **Usage**:
+  ```sh
+  export SSH=/opt/homebrew/bin/ssh
+  ```
+  ```powershell
+  $env:SSH = "'C:\Program Files\Git\usr\bin\ssh.exe'"
+  ```
+- **Note**: On Windows some paths still follow `PATH`, among them the guest
+  mount point and `limactl shell`'s working directory, so point `SSH` at the
+  install that comes first on `PATH`. `limactl guest-install` ignores this
+  variable altogether.

website/content/en/docs/config/vmtype/qemu.md

@@ -11,6 +11,14 @@ Recommended QEMU version:
 - v8.2.1 or later (macOS)
 - v6.2.0 or later (Linux)
 
+On a Windows host, "qemu" needs `ssh`, `scp`, and `ssh-keygen`; the
+[OpenSSH client](https://learn.microsoft.com/en-us/windows-server/administration/openssh/openssh_install_firstuse)
+that Windows installs by default provides all three. Mounts must use
+reverse-sshfs, because QEMU for Windows has no 9p support. Pinning
+[`sftpDriver: openssh-sftp-server`]({{< ref "/docs/config/mount#reverse-sshfs" >}})
+also requires `sftp-server.exe`, which comes from the optional OpenSSH Server
+feature.
+
 An example configuration:
 {{< tabpane text=true >}}
 {{% tab header="CLI" %}}

website/content/en/docs/config/vmtype/wsl2.md

@@ -37,12 +37,13 @@ containerd:
 
 ### Caveats
 - "wsl2" option is only supported on newer versions of Windows (roughly anything since 2019)
+- Windows installs an OpenSSH client in `C:\Windows\System32\OpenSSH\`, and the WSL2 driver needs no other SSH binaries
 
 ### Known Issues
 - "wsl2" currently doesn't support many of Lima's options. See [this file](https://github.com/lima-vm/lima/blob/master/pkg/wsl2/wsl_driver_windows.go#L19) for the latest supported options.
 - When running lima using "wsl2", `${LIMA_HOME}/<INSTANCE>/serial.log` will not contain kernel boot logs
 - WSL2 requires a `tar` formatted rootfs archive instead of a VM image. Standard VM disk images (like `.qcow2`, `.raw`, etc.) or `.squashfs` images cannot be natively imported by WSL2.
-- Windows doesn't ship with ssh.exe, gzip.exe, etc. which are used by Lima at various points. The easiest way around this is to run `winget install -e --id Git.MinGit` (winget is now built in to Windows as well), and add the resulting `C:\Program Files\Git\usr\bin\` directory to your path.
+- Lima unpacks a `.tar.gz` rootfs on its own, but a `.tar.xz`, `.tar.bz2`, or `.tar.zst` one needs the matching `xz`, `bzip2`, or `zstd` binary on your `PATH`, and Windows ships none of them.
 
 ### Rootfs Image Requirements & Building Custom Images