Re: [PATCH v6 01/14] dt-bindings: remoteproc: qcom,pas: Add iommus property

From: Mukesh Ojha

Date: Wed Nov 05 2025 - 03:34:12 EST


On Wed, Nov 05, 2025 at 08:17:14AM +0100, Krzysztof Kozlowski wrote:
> On 04/11/2025 08:35, Mukesh Ojha wrote:
> > Most Qualcomm platforms feature Gunyah hypervisor which handles IOMMU
>
> I don't think that's true. Washn't Gunyah something new? Like since
> SM8550? Look how many Qualcomm platforms we have in the arm/qcom.yaml
> bindings - for sure most of them are not post SM8550.


I should have rephrased it, thanks

"Qualcomm platform which feature QHEE based hypervisor or a module in Gunyah
... "

>
> > configuration for remote processor and when it is not present, the
> > operating system must perform these configurations instead and for that
> > firmware stream should be presented to the operating system. Hence, add
> > iommus property as optional property for PAS supported devices.
>
> So which platforms actually need to do this?

As I said above, almost every platform which features QHEE or Gunyah
hypervisor that support PAS based remoteproc subsystem should have this.

>
> I really do not understand why you are adding this to SDX55 and several
> others.

Firmware IOMMU context bank was always managed by QHEE hypervisor or
Gunyah it is more of never mentioned schema in PAS schema. So, even
SDX55 should have these as optional.

>
>
>
> Best regards,
> Krzysztof

--
-Mukesh Ojha