I'm pretty new to linux. I've got a fedora 24 workstation setup as my kvm machine. I'm using a GTX 1070 GPU, reserving it's id with VFIO, and then passing it through to my windows guest.

I also have a GTX 210 which I'd like to use as the primary gpu for fedora install. The problem is that my motherboard is choosing the GTX 1070 over the 210 in all PCI-E configurations, and doesn't seem to have an option to manually select the default GPU, so linux is defaulting to the 1070. As linux boots, the 1070 seems to get reserved and then blacks out. The 210 is never selected as the default GPU, and then I am stuck not being able to do anything.

How do I have linux default to the GTX 210 on startup?

I think it should be corrected by hardware settings:
1. Try to find PCI-E order in BIOS,
2. If BIOS cannot set default PCI-E slot, then re-order cards physically - put GTX 210 to first PCI-E slot (usually closer to CPU).

Post motherboard model, so we can see what hardware do You have.

try adding fbcon=map:0 as a boot option to the linux line of grub.