Hi,
I’m trying to assign my external GPU in a Razer Core X case connected on the thunderbolt 3 port of my T470. Unfortunately, if I start a VM where the thunderbolt related hardware are assigned, on R4.1 the system freezes, on R4.2 it reboots.
Did someone succeed at this before?
Hi, solene. Thanks for your nvidia drivers guide.
How is it going? I want to try external gpu passthrough too in near future (got rx580)
The few tries I did just ended up as instant reboot of the system when starting the HVM 
Following the recent guides about Gaming HVM and VirtualGL, I got a bit further.
With the hide_pci kernel option, the system doesn’t reboot anymore. But yet, I’ve not been able to use the GPU for rendering or its display, but it’s progress. I have an NVIDIA card in it, I’ll swap with an AMD because the support should be easier, I won’t have to fight with nouveau 
and struggle installing the proprietary driver.
it’s actually possible, I’m continuing in the Gaming HVM guide