I used "dma_alloc_coherent( )" as described in this thread (https://sourceforge.net/p/genode/mailman/message/34685275/) to allocate shared memory between the trustzone worlds in the tz_vmm example on i.mx53 qsb. It works well. But my questions is how do we  prevent the normal world from modifying this shared buffer while it is being used by the secure world. Thanks in advance for answers.

Kind regards,

Joseph