We'll go through properly updating GRUB to pass various kernel parameters for our Hypervisor setup needed for virtualization, and IOMMU usage
Start by using your favorite terminal text editor. In this example, we'll be using nano
sudo nano /etc/default/grub
We'll need to check our GRUB CMD Line flags and add various ones depending on the users' hardware.
| Kernel Parameter Intention | AMD | Intel | Both |
|---|---|---|---|
| Enable SR-IOV at kernel level | intel_iommu=on | ||
| Set IOMMU to Passthrough Mode | iommu=pt | ||
| Disable Kernel EFI Framebuffer | video=efifb:off |
Example GRUB configuration for an AMD CPU
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX="rootfstype=ext4 iommu=pt video=efifb:off"
Example GRUB configuration for an Intel CPU
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX="rootfstype=ext4 intel_iommu=on iommu=pt video=efifb:off"
When you're done make sure you use grub-mkconfig to update the GRUB Bootloader
sudo grub-mkconfig -o /boot/grub/grub.cfg
A Restart is required to apply changes, and should be done now.
You can now verify that the changes were made, by checking the current parameters booted with
cat /proc/cmdline
Example Output
[royalgraphx@hypervisor ~]$ cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-linux-zen root=UUID=00000000-0000-0000-0000-000000000000 rw rootfstype=ext4 iommu=pt video=efifb:off loglevel=3 quiet
If all looks good, you are now ready to continue!