Hi,
But also, this issue isn't something that only affects graphic devices, right? AFAIU from [1] and [2], the same issue happens if a PCI device has to be bound to vfio-pci but already was bound to a host driver.
Nope. There is a standard procedure to bind and unbind pci drivers via sysfs, using /sys/bus/pci/drivers/$name/{bind,unbind}.
Yes, but the cover letter says:
"Users often employ kernel command line arguments to disable conflicting drivers or perform unbinding in userspace to avoid this"
Thats helpful at times to deal with driver and/or hardware quirks. Example: Years ago drm drivers used to be horrible when it came to unbind, leaving oopses and panics left & right when you tried (luckily it works much better these days).
[ leaving this here for completeness, snipping the remaining reply, noting that we are on the same page now ]
thanks & take care, Gerd