Re: [PATCH v3] arm64: defconfig: Enable QCOMTEE on Qualcomm SM8650+

[Harshal Dev <harshal.dev@oss.qualcomm.com>]

Hi all,

On 12/12/2025 6:55 AM, Sumit Garg wrote:
> On Wed, Dec 10, 2025 at 02:35:19PM +0530, Harshal Dev wrote:
>> Hi Bjorn,
>>
>> On 12/10/2025 9:21 AM, Bjorn Andersson wrote:
>>> On Mon, Dec 8, 2025 at 10:14 PM Dmitry Baryshkov
>>> <dmitry.baryshkov@oss.qualcomm.com> wrote:
>>>> On Tue, 9 Dec 2025 at 07:58, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>>>>>
>>>>> On 08/12/2025 13:18, Harshal Dev wrote:
>>>>>> Enable QCOMTEE driver on Qualcomm SM8650+ SoCs to facilitate communication
>>>>>> with the Qualcomm Trusted Execution Environment (QTEE).
>>>>>> (No enablement required in DTS files since QCOMTEE device is dynamically
>>>>>> registered by the QCOM_SCM firmware driver)
>>>>>>
>>>>>> Signed-off-by: Harshal Dev <harshal.dev@oss.qualcomm.com>
>>>>>> ---
>>>>>> Changes in v3:
>>>>>> - Updated the commit message to reflect the supported Qualcomm platforms.
>>>>>> - Link to v2: https://lore.kernel.org/r/20251205-qcom_qcomtee_defconfig-v2-1-c92560b0346e@qti.qualcomm.com
>>>>>>
>>>>>
>>>>> I gave you the exact example to follow. Maybe it is not that important
>>>>> for others, so I will not object, but OTOH it is important for me, thus
>>>>> I will not give reviewed by. I damn asked VERY CLEARLY:
>>>>>
>>>>> "Just mention which UPSTREAM boards (which you called Qualcomm
>>>>> platforms) use this driver."
>>>>
>>>> +1 Here. Defconfig changes mention devices, not SoC families.
>>>>
>>>
>>> I don't agree that you have to mention a specific board, if the
>>> feature is used by all boards. But I think the commit message should
>>> make _that_ clear.
>>>
>>
>> Thanks for this input Bjorn. I gather we are now aligned that the board
>> information is not required.
>>
>> Then the other part to this is how to provide information on the particular
>> SoCs using this.
>>
>>> On the contrary, the commit message says that we're enabling
>>> CONFIG_QCOMTEE because it's used on "SM8560+". What does the plus
>>> mean?
>>
>> I took reference from similar commits merged earlier where the plus seemed
>> to indicate that all Qualcomm SoCs from 'SM8650' on-wards, that is, SM8750,
>> SM8850 and so on. It felt that the plus sign is self-explanatory since it
>> has been used already. But sure, maybe we can be explicit from now on and say
>> from 'Qualcomm SM8650 onwards'.
>>
>> commit c5d02bbaa217b2454ba1ce7528113aa2ecf14f3c
>>
>>> Also, the driver isn't enabled "on Qualcomm SM8650+", it's enabled in
>>> the Am64 defconfig, i.e. it's enabled on all Arm64 boards - the
>>> question that should be answered by the commit message is "why?".
>>>
>>
>> Even though we are enabling this via the arm64 defconfig, it is not true that
>> the driver is applicable for all arm64 boards. The simple reason being that
>> the QTEE firmware OS that the driver communicates with runs only on Qualcomm
>> SoCs using arm64 CPUs with ARM TrustZone technology.
>>
>> This is why I would try to avoid a commit message which claims the the driver
>> is applicable to all arm64 boards.
>>
>> Based on all this, I am thinking perhaps it would be better to say that the
>> patch enables QCOMTEE driver for Qualcomm SoCs with arm64 CPUs? We could drop
>> mentions of specific SM8x50 models with HDK/MTP boards since the feature is
>> agnostic to those?
> 
> AFAIK, the QCOMTEE driver works on the Qcom SoCs based on arm64 which supports
> the SMCInvoke protocol. So we should be explicit about it. Regarding
> mention of reference publicly available boards, I can see how it can be useful
> for the community to test QTEE based apps. If you can mention say
> example RB3Gen2 supports QTEE driver at least then it will be helpful.
> 

Based on consolidated feedback on this thread, I am thinking of the following
commit message, let me know if this is a go from everyone's perspective:

"
arm64: defconfig: Enable QCOMTEE for Qualcomm SoCs using arm64 CPUs

Enable QCOMTEE driver as a module for Qualcomm SoCs based on arm64 CPUs and
supporting the SMCInvoke protocol for communication with the Qualcomm Trusted
Execution Environment (QTEE).

The driver is tested on a Qualcomm RB3Gen2 board by loading and executing a
Trusted Application via tests hosted at www.github.com/qualcomm/minkipc.
"

Regards,
Harshal

> -Sumit
> 
> [...]