Re: [PATCH v3 11/15] media: qcom: Switch to generic PAS TZ APIs

Trilok Soni
2026-04-07T22:14:31Z

On 4/6/2026 4:42 AM, Sumit Garg wrote:
> Hi Jorge,
>
> On Fri, Apr 03, 2026 at 11:37:07AM +0200, Jorge Ramirez wrote:
>> On 27/03/26 18:40:39, Sumit Garg wrote:
>>> From: Sumit Garg <sumit.garg@oss.qualcomm.com>
>>>
>>> Switch qcom media client drivers over to generic PAS TZ APIs. Generic PAS
>>> TZ service allows to support multiple TZ implementation backends like QTEE
>>> based SCM PAS service, OP-TEE based PAS service and any further future TZ
>>> backend service.
>>
>> OP-TEE based PAS service relies on the linux driver to configure the
>> iommu (just as it is done on the no_tz case). This generic patch does
>> not cover that requirement.
>
> That's exactly the reason why the kodiak EL2 dtso disables venus by
> default in patch #1 due to missing IOMMU configuration.
>
>>
>> Because of that, it is probably better if the commit message doesnt
>> mention OP-TEE and instead maybe indicate that PAS wll support TEEs that
>> implement the same restrictions that QTEE (ie, iommu configuration).
>
> The scope for this patch is to just adopt the generic PAS layer without
> affecting the client functionality.
>
>>
>> I can send an RFC for OP-TEE support based on the integration work being
>> carried out here [1]
>
> @Vikash may know better details about support for IOMMU configuration
> for venus since it's a generic functionality missing when Linux runs in
> EL2 whether it's with QTEE or OP-TEE.
>
> However, feel free to propose your work to initiate discussions again.

Vikas and team depends on some of the IOMMU patches to get accepted
before they enable the EL2 venus support. Please reach out to him
and Prakash Gupta at Qualcomm.

>
>>
>> [1] https://github.com/OP-TEE/optee_os/pull/7721#discussion_r3016923507
>
> -Sumit