$ cat /proc/cmdline
initrd=\amd-ucode.img initrd=\initramfs-linux.img root=UUID=myuuid rw iommu=1 amd_iommu=on iommu=pt

$ cat /boot/loader/entries/arch.conf #using systemd-boot
title	Arch Linux
linux	/vmlinuz-linux
initrd	/amd-ucode.img
initrd /initramfs-linux.img
options root=UUID=myuuid rw iommu=1 amd_iommu=on iommu=pt

$ sudo dmesg | grep IOMMU # I've already activated it in BIOS :)
[    0.318760] pci 0000:00:00.2: AMD-Vi: IOMMU performance counters supported
[    0.319589] pci 0000:00:00.2: AMD-Vi: Found IOMMU cap 0x40
[    0.320060] perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 counters/bank).
[    0.333308] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel <[email protected]>

$ cat mypcinfo
OS: Arch Linux x86_64
Kernel: 5.12.8-arch1-1
CPU: AMD Ryzen 7 3700X (16) @ 3.600GHz
GPU: NVIDIA GeForce RTX 2060 SUPER

$ cat ./qemu.d/win10/prepare/begin/start.sh
#!/bin/bash

# set debugging
set -x

# load variables
source "/etc/libvirt/hooks/kvm.conf"

# stop display manager
#systemctl stop sddm.service
systemctl stop i3wm.service --user
# unbind VTConsoles
echo 0 > /sys/class/vtconsole/vtcon0/bind
echo 0 > /sys/class/vtconsole/vtcon1/bind

# unbind efi framebuffer
echo efi-framebuffer.0 > /sys/bus/platform/drivers/efi-framebuffer/unbind

# avoid race condition
sleep 12

# unload nvidia
modprobe -r nvidia_uvm
modprobe -r nvidia_drm
modprobe -r nvidia_modeset
modprobe -r drm_kms_helper
modprobe -r drm
modprobe -r nvidia

# unbind the GPU
virsh nodedev-detach $VIRSH_GPU_VIDEO
virsh nodedev-detach $VIRSH_GPU_AUDIO

# load vfio
modprobe vfio_pci
$ cat /etc/libvirt/hooks/kvm.conf
## Virsh devices
VIRSH_GPU_VIDEO=pci_0000_07_00_0
VIRSH_GPU_AUDIO=pci_0000_07_00_1