Accessing motherboard serial port (ttyS2, FPGA-based) inside Proxmox VM

inceabdullah

New Member
Jul 14, 2024
1
0
1
Hello,


I have a problem, I try to explain, sorry for my English.


Before, I was using Ubuntu on bare metal server. I have a custom FPGA-based serial port on motherboard (I think it is added via FPGA on board). In Ubuntu, I can see ttyS2 in dmesg, and when I install my custom FPGA driver, I can communicate with device using minicom.


Now I install Proxmox on same machine.


On Proxmox host:


  • I can see /dev/ttyS*
  • But in dmesg I only see ttyS0, I don’t see ttyS2 anymore

So now I am confused.


My goal is to use this FPGA serial device inside an Ubuntu VM.


My questions:


  • If this serial port is coming from FPGA on motherboard, is it still possible to passthrough to VM?
  • Should I:
    • pass /dev/ttyS2 as serial device to VM
    • or passthrough whole PCI device (if it exists)?
  • For my custom FPGA driver:
    • is installing inside VM enough?
    • or I must also install it on Proxmox host so ttyS2 appears?
  • Why Proxmox does not show ttyS2 in dmesg but Ubuntu did before?

I am not sure if problem is driver missing on host or different kernel behavior.


Thank you for any help