Fedora Build ACS Override Patch Kernel

Add RPM Fusion

sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

Install the dependencies to start building your own kernel.

sudo dnf install fedpkg fedora-packager rpmdevtools ncurses-devel pesign fedora-packager fedora-review rpmdevtools numactl-devel pesign
sudo dnf groupinstall "Development Tools"
sudo dnf build-dep kernel

Set up your home build directory (if you haven't ever built any RPMs before)


Install the kernel source and finish installing dependencies.

cd ~/rpmbuild/SOURCES
sudo dnf download --source kernel
rpm2cpio kernel-* | cpio -i --make-directories
mv kernel-*.src.rpm ../SRPMS
cd ../SRPMS
rpm -Uvh kernel-*.src.rpm
vim ~/rpmbuild/SPECS/kernel.spec

Add the two lines near the top of the spec file.

# Set buildid
%define buildid .acs

# ACS override patch
Patch1000: add-acs-override.patch

Download ACS path

cd ~/rpmbuild/SOURCES/
wget https://git.myhypervisor.ca/dave/fedora-acs-override/raw/master/acs/add-acs-override.patch

Re-create new SRC RPM

rpmbuild -bs ~/rpmbuild/SPECS/kernel.spec

Upload to Copr (need account)

New file located in ~/rpmbuild/SRPMS/kernel-4.20.3-200.acs.fc29.src.rpm


(Wait 10hours for RPM to build)

Enable new repo

dnf copr enable user/pkg-name

Install new kernel

sudo dnf update kernel-4.20.6-200.acs.fc29 kernel-devel-4.20.6-200.acs.fc29 --disableexcludes all --refresh

Update and reboot

Update GRUB file /etc/default/grub, change GRUB_CMDLINE to bellow

GRUB_CMDLINE_LINUX="rd.driver.pre=vfio-pci rd.driver.blacklist=nouveau modprobe.blacklist=nouveau rhgb quiet intel_iommu=on iommu=pt pcie_acs_override=downstream"

Rebuild GRUB's configuration

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Create or edit /etc/modprobe.d/local.conf, adding the line below:

install vfio-pci /sbin/vfio-pci-override.sh

Create or edit /etc/dracut.conf.d/local.conf, adding the line below:

add_drivers+="vfio vfio_iommu_type1 vfio_pci vfio_virqfd"
install_items+="/sbin/vfio-pci-override.sh /usr/bin/find /usr/bin/dirname"

Create a file /sbin/vfio-pci-override.sh with permissions 755 (file in this directory of the repo).


# This script overrides the default driver to be the vfio-pci driver (similar
# to the pci-stub driver) for the devices listed. In this case, it only uses
# two devices that both belong to one nVidia graphics card (graphics, audio).

# Located at /sbin/vfio-pci-override.sh

DEVS="0000:02:00.0 0000:02:00.1"

if [ ! -z "$(ls -A /sys/class/iommu)" ] ; then
for DEV in $DEVS; do
echo "vfio-pci" > /sys/bus/pci/devices/$DEV/driver_override

modprobe -i vfio-pci

Rebuild using dracut

sudo dracut -f --kver `uname -r`


Install (proprietary) nVidia drivers and remove/blacklist (open source) nouveau drivers.

sudo su -
dnf install xorg-x11-drv-nvidia akmod-nvidia "kernel-devel-uname-r == $(uname -r)" xorg-x11-drv-nvidia-cuda vulkan vdpauinfo libva-vdpau-driver libva-utils
dnf remove *nouveau*
echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf