Without enabling IOMMU and load vfio-pci, there is possibility of hang system
during poweroff and hang virt-manager.

Virt-manager does not complains about missing option, or does not clarify what
happens, just running VM is broken after trying to pass through PCI device
without do some task earlier.

Solution: made virt-manager check if IOMMU is enabled, etc. If check fail, show
message explaining, what user should do.

Solution 2: add virtualization configure page to Yast-OpenSUSE-Installer. User
could select server role, so add virtualization checkbox somewhere near. If
checked and user press next, virtualization configuration page will appear,
where user could add devices to pass through. If user do that, then check CPU
type, enable IOMMU and configure vfio-pci module.
Maybe integrate it with Virtualization page under Yast in future?