To ensure dracut does not load nouveau we need to explicitly disable it via
omit_drivers.
This change adds a method to drop in arbitary dracut conf files to an element
which are picked up by dracut-regenerate and included in the chroot where we
run dracut.
The disable-nouveau element just adds a conf file with
`omit_drivers += " nouveau"`
The default dracut conf files in /usr/lib include a similar file to omit the
nvidia kernel modules.
Change-Id: I6375e4843fd08d1410141fbbd8658042dcd5ad05
Closes-bug: 1842664
This ensures nouveau is not loaded at boot, which is required when installing
NVIDIA GPU drivers and to avoid issues with PCI passthrough of NVIDIA GPUs.
The option to disable kernel modesets ensures that it can be unloaded again if
it happens to be loaded after boot (e.g manually or implicitly by X).
bp tripleo-vgpu
Change-Id: I60815de86e7b22dfb39555af9d2d53564841e2ab
Related-bug: 1774674