Re: [PATCH RFC 0/3] firmware: arm_firme: introduce FIRME support for host attestation

[Yeoreum Yun <yeoreum.yun@arm.com>]

On Tue, Oct 20, 2026 at 11:36:20AM -0300, Jason Gunthorpe wrote:
> On Tue, Oct 20, 2026 at 03:13:19PM +0100, Yeoreum Yun wrote:
> > > I wouldn't over complicated it. We already have smccc bus to do this,
> > > we don't need layered stacks of busses here. Just change smccc bus to
> > > be able to break up the multi-function SMC into several devices.
> > 
> > I think my explaination was poor. Apologise...
> > I'm not saying another bus making but just wrapper of smccc-bus APIs
> > for firme specific and definietly, this would separate the
> > multi-function SMC to defien each firme device (attestation and IDE).
> 
> I don't see that kind of complexity is necessary.. I think it is
> better to just have the root smcc bus spawn them 
> 
> > But, the *base* is common. and I couldn't find any proper location to
> > deploy *common* code unless making arm_firme.
> 
> What common code excatly?
> 
> There shouldn't be? Getting an attestation is entirely orthogonal to
> set link ide, for example?
> 
> If you can identify what you think would ever be common that might
> help clarifgy what to do..

I mean the BASE service of firme and typical example is shared buffer
allocation. I agree IDE and attestaion service are orthogonal. but
in case of base-service is not. it could be used for both service.

Therefore, the firme_device wouldn't export all functions. In case of
attestaion, it's enough to export base-service and attestation-service
only. for the IDE, base-service and ide-service via union.

Also We don't need to export base-service firme device as part of smccc
device. It's enough to export two devices -- attestation and IDE via
base_ops. But, to share the base-service opeerations to both devices,
I think it would be better to have current arm_fimre layer.

-- 
Sincerely,
Yeoreum Yun