vfio/iommufd: Introduce a VFIOIOMMU iommufd QOM interface

As previously done for the sPAPR and legacy IOMMU backends, convert
the VFIOIOMMUOps struct to a QOM interface. The set of of operations
for this backend can be referenced with a literal typename instead of
a C struct.

Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
4 files changed