Hi Stefano and Oleksii,
Let me start with a bit of process. This is discussion is getting fairly
difficult to follow.... Can you please trim unrelevant bits when replying?
On 22/06/2025 22:57, Stefano Stabellini wrote:
On Thu, 19 Jun 2025, Oleksii Moisieiev wrote:
On 18/06/2025 03:35, Stefano Stabellini wrote:
On Thu, 12 Jun 2025, Oleksii Moisieiev wrote:
On 23/05/2025 23:19, Stefano Stabellini wrote:
On Mon, 19 May 2025, Oleksii Moisieiev wrote:
From: Grygorii Strashko<grygorii_stras...@epam.com>
the same (smc-id and shmem) for both the BSP case (no Xen) and the Xen
case (Dom0 domain).
Meanwhile, the Xen management agent's SCMI node and configuration are
expected to be placed under /chosen.
This approach ensures that the Host DT remains as unchanged as possible.
Yes, my main point is that all the device tree information, except for
what is under /chosen, should be left unchanged between the BSP case (no
Xen) and the Xen case.
We have freedom to decide:
- the information we put under /chosen and how to interpret it
- how to use the information under /firmware/scmi when Xen is present
Currently:
The Host DT /firmware/scmi node requires modification to point to the
Xen management agent by changing
the smc-id and shmem values.
I don't think we should require changes to /firmware/scmi in the host DT
when Xen is present.
Often, people don't know when or if Xen is present at the time the
Device Tree is generated. So it is best to avoid modification (outside
of /chosen).
I am probably missing something. But it looks like TF-A requires to
suport multi-agent so Xen can use it. Am I correct?
Furthermore, I can't tell why the multi-agent support is Xen specific.
Surely, you may want something similar with other hypervisors? If not,
then my next question is why does Xen needs to do things differently?
Cheers,
--
Julien Grall
