Serial port passthrough in a HA environment / HA priorisation question

Hey folks,

I did not find any information about serial port passthrough for Proxmox VE 2.x, only for 1.X. But as a special addition, what about a serial port passthrough in a HA environment?

Here's the scenario:

We run Webresetters made by ICO (see webresetter.de), the TKS hub is accessed via serial port. We want to migrate that server to a virtual HA platform. I think the serial port should work like in PVE 1.x, but what about the HA part? When Host1 goes down, Host2 will take over the VMs on Host2, but then the serial port will be offline or not connected. I never saw serial Y cables :)

Is there any way to priorise virtual machines, so when Host1 is available the virtual machine with the virtual serial port connected to the physical serial port on Host1 should run on Host1 and not on Host2? I think we can live with the downtime of the serial port when Host1 goes down for updates, hardware maintenance etc.

Thanks for any information and/or ideas.