Re: [PATCH] xen/arm: Skip Xen specific nodes/properties from hwdom /chosen node

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 11 Sep 2023, Julien Grall wrote:
> On 11/09/2023 13:34, Michal Orzel wrote:
> > Host device tree nodes under /chosen with compatible string
> > "xen,evtchn-v1", "xen,domain-shared-memory-v1" are Xen specific and not
> > meant to be exposed to hardware domain.
> 
> So, how dom0 is meant to discover the static event channel, shared memory it
> can use?

As they are static, they don't necessarily need to be discovered: they
could be hard-coded. I realize we didn't commit the design doc for the
static event channel feature, but it had:
https://marc.info/?l=xen-devel&m=165245272905876

---
+There is no need to describe the static event channel info in the domU device
+tree. Static event channels are only useful in fully static configurations,
+and in those configurations the domU device tree dynamically generated by Xen
+is not needed.
---

But in any case, even if we wanted to generated/expose the static event
channels via Device Tree, the information on the host device tree is in
the "wrong" format. That's meant for Xen and has all the static event
channels, including the ones not relevant for Dom0. So I think that in
any case we should filter them out here (and regenerate as necessary).