The section https://docs.redhat.com/en/documentation/openshift_container_platform/4.19/html/virtualization/managing-vms#virt-access-configuration-considerations_virt-accessing-vm-ssh is already great, and a similar section for VNC and serial would be nice.

Already available ways of troubleshooting VM Guests without networking OpenShift Virtualization

In the OpenShift Virtualization environment you can access VM guests by using the web console or by using virtctl commands from the command-line interface (CLI).

Connecting to VMs using the VNC console

You can connect to the VNC console of a virtual machine (VM) by using the OpenShift Container Platform web console, as documented in the first two steps in Connecting to the serial console by using the web console  .

Alternatively you can use the virtctl command-line tool to connect to the VNC console of a running virtual machine. The installation of the virtctl command line tool is documented in Installing virtctl and the usage is documented in Connecting to the VNC console by using virtctl.

• Recommended for troubleshooting VMs.
• Not recommended for high-traffic applications like VDI (Virtual Desktop Infrastructure) because of the burden on the API server.
• The API server must be able to handle the traffic load.
• The clients must be able to access the API server.
• The clients must have access credentials for the cluster.

Connecting to VMs using the serial console

You can connect to the serial console of a virtual machine (VM) by using the OpenShift Container Platform web console, as documented in Connecting to the serial console by using the web console  .

Alternatively you can use the virtctl command-line tool to connect to the serial console of a running virtual machine. The installation of the virtctl command line tool is documented in Installing virtctl and the usage is documented in Connecting to the serial console by using virtctl. 

• The clients must be able to access the API server.
• The clients must have access credentials for the cluster.
• (The API server must be able to handle the traffic load.)