1. Find the device ID to blacklist

nick@swae-ws:~$ lspci | grep VGA
43:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 7448
63:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 7448

In this case let’s blacklist 43:00

2. Find all devices on bus

Look for the bus ID, which should reveal all devices attached to the GPU PCI-E bus

nick@swae-ws:~$ lspci -nn | grep 43:00
43:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:7448]
43:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:ab30] 

Note down the device IDs, in this case its 1002:7448 and 1002:ab30

3. Update GRUB boot args

sudo nano /etc/default/grub
# Update the line that starts with "GRUB_CMDLINE_LINUX_DEFAULT"
# Append to the end: "vfio-pci.ids=1002:7448,1002:ab30"
# The result should look like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vfio-pci.ids=1002:7448,1002:ab30"
# Ctrl+X -> Y -> Enter
sudo update-grub

Reboot the system, after reboot, the device will not be handed over to the driver. Make sure displays continue to work (Eg connect to another adapter)

4. Validate

lspci -nnv

Find the device in question, find the line Kernel driver in use: . It should show vfio-pci