Hi, thanks you ! 
I think I have an idea on what is different between my setup and your setup.
In the output of your lspci command, this line is interesting:
Region 1: Memory at 600000000 (64-bit, prefetchable) [size=8G]
8G is not the usual default BAR size. The standard BAR size is 256M (what I have on my config):
Region 1: Memory at e0000000 (64-bit, prefetchable) [size=256M]
So your motherboard seems to not use the standard BAR size (maybe “resizable bar” option is activated on your motherboard and you can’t change it).
I did some tests on my setup.
I enabled “Resizable bar” in my bios, and tried to launch my gpu hvm. And it crashed the same way it crashed for you before. I notice that the BAR size changed to:
Region 1: Memory at c00000000 (64-bit, prefetchable) [size=16G]
Then I switched to 2G instead of my 3.5G, and it work with “resizable bar” activated.
I will test other values instead of 2G and 3.5G, and I will try to find someone with a more advanced motherboard to check if the difference of value depend on the option “resizable bar” or not.