Simplify the VFIOIOMMUClass interface by removing the dma_map_file
handler. Move the logic to decide between the standard virtual and
file-backed mapping into the IOMMUFD backend, utilizing the
MemoryRegion already passed to the dma_map handler.
This removes redundant dispatch logic from the generic container layer
and let backends to manage their own mapping strategies. This is
similar to the vfio-user implementation.
Reviewed-by: Alex Williamson <alex@shazbot.org>
Link: https://lore.kernel.org/qemu-devel/20260608055758.359002-1-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
877da38313