In the case of VFIO, the unrealize callback is too early to munmap the
BARs. The munmap must be delayed until memory accesses are complete.
To do this, split vfio_unmap_bars in two. The removal step, now called
vfio_unregister_bars, remains in vfio_exitfn. The reclamation step
is vfio_unmap_bars and is moved to the instance_finalize callback.
Similarly, quirk MemoryRegions have to be removed during
vfio_unregister_bars, but freeing the data structure must be delayed
to vfio_unmap_bars.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>