docs: virtio: add section about available drivers and samples

This commit adds sections to the virtio docs with the currently
supported transfer methods, drivers and samples

Signed-off-by: Jakub Michalski <jmichalski@antmicro.com>

Author: jmichalski-ant

doc/hardware/virtualization/virtio.rst

@@ -123,6 +123,31 @@ virtqueue has to be acquired using :c:func:`virtio_get_virtqueue`. To send data
 will be invoked once the device returns the given descriptor chain. After that, the virtqueue has to be notified using
 :c:func:`virtio_notify_virtqueue` from the Virtio API.
 
+Guest-side Virtio drivers
+*************************
+Currently Zephyr provides drivers for Virtio over PCI and Virtio over MMIO and drivers for two devices using virtio - virtiofs, used
+to access the filesystem of the host and virtio-entropy, used as an entropy source.
+
+Virtiofs
+=========
+This driver provides support for `virtiofs <https://virtio-fs.gitlab.io/>`_ - a filesystem allowing a virtual machine guest to access
+a directory on the host. It uses FUSE messages to communicate between the host and the guest in order to perform filesystem operations such as
+opening and reading files. Every time the guest wants to perform some filesystem operation it places in the virtqueue a descriptor chain
+starting with the device readable part, containing the FUSE input header and input data, and ending it with the device writeable part, with place
+for the FUSE output header and output data.
+
+Virtio-entropy
+==============
+This driver allows using virtio-entropy as an entropy source in Zephyr. The operation of this device is simple - the driver places a
+buffer in the virtqueue and receives it back, filled with random data.
+
+Virtio samples
+**************
+A sample showcasing the use of a driver relying on Virtio is provided in :zephyr:code-sample:`virtiofs`. If you wish
+to check code interfacing directly with the Virtio driver, you can check the virtiofs driver, especially :c:func:`virtiofs_init`
+for initialization and :c:func:`virtiofs_send_receive` with the :c:func:`virtiofs_recv_cb` for data transfer to/from
+the Virtio device.
+
 API Reference
 *************