configure grub

add the following to /etc/default/grub:

for intel:

GRUB_CMDLINE_LINUX_DEFAULT="quiet ... intel_iommu=on"

for amd:

GRUB_CMDLINE_LINUX_DEFAULT="quiet ... amd_iommu=on"

re-configure your grub:

grub-mkconfig -o /boot/grub/grub.cfg

isolating gpu

find the device id of the gpu:

lspci -nn

edit /etc/modprobe.d/vfio.conf file and adding the following line with your ids:

options vfio-pci ids=10de:13c0,10de:0fbb