Function devices::pci::coiommu::gfn_to_dtt_pte

fn gfn_to_dtt_pte(
    mem: &GuestMemory,
    dtt_level: u64,
    dtt_root: u64,
    dtt_iter: &mut DTTIter,
    gfn: u64
) -> Result<*const AtomicU32>