Hi,
On Tue, Jun 14, 2016 at 11:51 PM, machiry aravind
<machiry_msidc@hotmail.com> wrote:
> Hi all,
>
>
> Is there any reason, why we expect all the memref param physical address to
> be in MEM_AREA_NSEC_SHM?
Current design is that OP-TEE tells normal world which memory to use
as shared memory, it doesn't make sense for OP-TEE to accept pointers
to memory out side that range.
>
>
> More specifically, why is it hard to map arbitrary non-secure user-space
> pages into TA?
If you want to map them, you need to make sure that they aren't
unmapped (or more specifically reused for something else) while used
in secure world.
>
>
> MEM_AREA_NSEC_SHM restriction imposes unnecessary limit on TA.
>
> If I want to implement some integrity checking mechanism on large sections
> of memory, this restriction makes it almost impossible.
Yes, but the purpose of this memory is to be used as shared memory for
communication between secure and non-secure world. You're looking for
something much more complex.
Long term I think we'd like to be able to map arbitrary non-secure
memory as parameters for TAs, both to make some use cases more
efficient but also to make MEM_AREA_NSEC_SHM optional in some
configuration. I'm not aware of any concrete plans though.
Regards,
Jens