[PATCH v22 02/10] firmware: arm_rmm: Check for RMI support at init

[Suzuki K Poulose]

On 14/10/2026 13:05, Sudeep Holla wrote:
> On Wed, Oct 14, 2026 at 12:06:54PM +0100, Suzuki K Poulose wrote:
> 
> [...]
> 
>>
>> Then it is RMM's problem if it doesn't check that the right level of
>> SMCCC version is not implemented by the EL3. Also, where do we stop
>> the checks ? e.g., We need SMCCC >= v1.3, when SVE is supported.
>> And >= v1.4 if SME is supported. Shouldn't we leave this to the RMM
>> to verify on init and fail the init ? I can raise this with the
>> tf-RMM team.
> 
> Fair enough for v1.3+/SME/SVE checks, but RMI interface relying on more
> that 8 input registers for one or more of it's interfaces (e.g.
> RSI_ATTESTATION_TOKEN_INIT, RSI_MEASUREMENT_EXTEND, ...etc) indicate
> it can't work with SMCCC v1.1 or below

Fyi, those are RSI interfaces (Realm Guest facing) and we could add the
checks there. This series is the Host facing interface. That said I
will send a fixup to add the check for v1.2 for RMI too.

Thanks for the feedback, both!

Cheers
Suzuki

> .
> So IMO check for v1.2+ is completely justified here.
>