docs: virtiofs added to docs and release-notes

Author: angelcerveraroldan

config/doc/ignition.yaml

@@ -172,12 +172,23 @@ root:
           desc: the list of filesystems to be configured. `device` and `format` need to be specified. Every filesystem must have a unique `device`.
           children:
             - name: device
-              desc: the absolute path to the device. Devices are typically referenced by the `/dev/disk/by-*` symlinks.
+              desc: the absolute path to the device. Devices are typically referenced by the `/dev/disk/by-*` symlinks. For virtiofs, this is the tag name.
+              transforms:
+                - regex: " For virtiofs, this is the tag name."
+                  replacement: ""
+                  if:
+                    - variant: ignition
+                      max: 3.6.0
             - name: format
-              desc: the filesystem format (ext4, btrfs, xfs, vfat, swap, or none).
+              desc: the filesystem format (ext4, btrfs, xfs, vfat, virtiofs, swap, or none).
               # not part of the primary key, but required by validation
               required: true
               transforms:
+                - regex: "virtiofs, "
+                  replacement: ""
+                  if:
+                    - variant: ignition
+                      max: 3.6.0
                 - regex: "swap, or none"
                   replacement: "or swap"
                   if:

docs/configuration-v3_7_experimental.md

@@ -71,8 +71,8 @@ The Ignition configuration is a JSON document conforming to the following specif
     * **_spares_** (integer): the number of spares (if applicable) in the array.
     * **_options_** (list of strings): any additional options to be passed to mdadm.
   * **_filesystems_** (list of objects): the list of filesystems to be configured. `device` and `format` need to be specified. Every filesystem must have a unique `device`.
-    * **device** (string): the absolute path to the device. Devices are typically referenced by the `/dev/disk/by-*` symlinks.
-    * **format** (string): the filesystem format (ext4, btrfs, xfs, vfat, swap, or none).
+    * **device** (string): the absolute path to the device. Devices are typically referenced by the `/dev/disk/by-*` symlinks. For virtiofs, this is the tag name.
+    * **format** (string): the filesystem format (ext4, btrfs, xfs, vfat, virtiofs, swap, or none).
     * **_path_** (string): the mount-point of the filesystem while Ignition is running relative to where the root filesystem will be mounted. This is not necessarily the same as where it should be mounted in the real root, but it is encouraged to make it the same.
     * **_wipeFilesystem_** (boolean): whether or not to wipe the device before filesystem creation, see [Ignition's documentation on filesystems](https://coreos.github.io/ignition/operator-notes/#filesystem-reuse-semantics) for more information. Defaults to false.
     * **_label_** (string): the label of the filesystem.

docs/release-notes.md

@@ -11,6 +11,7 @@ nav_order: 9
 ### Features
 
 - Support reading configs from `/run/ignition` and `/etc/ignition/` in addition to `/usr/lib/ignition/`, searched in descending priority order ([#2221](https://github.com/coreos/ignition/pull/2221))
+- Add support for `virtiofs`
 
 ### Changes