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

edit /etc/mkinitcpio.conf and add the following:

MODULES="vfio vfio_iommu_type1 vfio_pci vfio_virqfd"

In the same file, also add modconf to the HOOKS line:

HOOKS="modconf"

backup your existing initramsfs image:

cp /boot/initramfs-linux.img /boot/default-initramfs-linux.img

rebuild initramfs:

mkinitcpio -g /boot/initramfs-linux.img