@roxie https://forums.centos.org/viewtopic.php?t=60531I would higjly reccomend looking into what's called a 'pci-stub' - its basically a way to tell the kernel to immediately park a PCI device with a dummy driver so it can be safely detached and reattached after the system has fully booted.
This is useful when you need the system to stay hands-off with a particular device like a GPU until you're fully booted and ready for something like vfio to pick it up (which I presume is for PCI paasthrough in your case - as it was for me)
If you're using UEFI to boot you may also need `dracut` to help you rebuild the init ramdisk to prevent the GPU driver from being loaded when the init image is passed to the kernel.
If you have any questions feel free to ask - it can take a while to grasp how it all fits together and my explanation may not convey the useful bits effectively for you.