docs: add references to Argo Linux driver sources and information

Add a section to the Argo design document to supply guidance on how to
enable Argo in Xen and where to obtain source code and documentation
for Argo device drivers for guest OSes, primarily from OpenXT.

Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

docs/designs/argo.pandoc

@@ -439,6 +439,51 @@ that teardown of any domain will not interfere with any Argo hypercall
 operation. It enables introducing granular locking without complex or
 error-prone lock acquisition logic.
 
+# Related Material
+
+## Enabling Argo in Xen
+
+To enable Argo in a build of the Xen hypervisor, please ensure that
+CONFIG_ARGO is enabled in the Xen hypervisor build configuration file.
+
+To make Argo available for use at runtime on a Xen system, please see the
+Argo settings in the Xen command line documentation.
+
+## Linux Argo drivers
+
+A Linux kernel device driver for Argo and corresponding Linux userspace
+software, libargo, that utilizes it for interdomain communication between
+application level software is available and maintained by the OpenXT Project,
+at:
+
+https://github.com/OpenXT/linux-xen-argo
+
+The repository contains the primary Linux kernel Argo driver, which is derived
+from the original XenClient v4v driver. The document at the following link
+describes planning and design notes from OpenXT community discussion for
+improvements to the driver:
+
+https://openxt.atlassian.net/wiki/spaces/DC/pages/775389197/New+Linux+Driver+for+Argo
+
+An alternative Linux Argo driver is also available in the same repository,
+implemented to explore a different approach for Linux to use the Argo
+primitives under the Vsock address family to allow socket communication between
+Xen domains.
+
+## v4v drivers
+
+A Windows driver for v4v has previously been used in XenClient and OpenXT
+which could be ported to Argo. It may require update for compatibility with
+recent versions of Windows software.
+
+https://github.com/OpenXT/xc-windows/tree/master/xenv4v
+
+The Linux, Windows and OSX guest tools for the Open Source HP uxen hypervisor
+contain drivers for v4v which are relevant as code bases of interest for
+porting or developing new guest OS drivers for Argo.
+
+https://github.com/uxen-virt/uxen/tree/ascara/vm-support
+
 # Future Work
 
 - Performance measurement and optimization