[RFC PATCH v7 02/13] mm: Add an allocator for CoCo shared memory

[Suzuki K Poulose]

On 22/09/2026 17:51, Jason Gunthorpe wrote:
> On Tue, Sep 22, 2026 at 05:25:58PM +0100, Catalin Marinas wrote:
>> Does the memset() post sharing logic work for pKVM as well? If nothing
>> clears it, we have a small window where guest data is leaked to the
>> host.
> 
> Same question for RMM? Or did they define that the RMM zeros on these
> transitions?

RMM doesn't "define" what exactly is written when a granule is 
transitioned to "DELEGATED" or "UNDELEGATED". But does guarantee that 
the contents are wiped after the transition. This may be:
  * RMM writing random bytes or 0s
  * Changing the MEC of the location.

See section A2.3.8 Granule wiping DEN0137 2.0-bet3

Cheers

Suzuki