[PATCH v3 1/2] dt-bindings: arm: xen: document Xen iommu device

[Robin Murphy]

On 2022-01-26 15:09, Sergiy Kibrik wrote:
> Hi Robin,
> 
>>
>> This could break Linux guests, since depending on the deferred probe
>> timeout setting it could lead to drivers never probing because the "IOMMU"
>> never becomes available.
>>
> 
> I've noticed no deferred probe timeouts when booting with this patch. Could you please explain more on how this would break guests?

Right now I think it would actually require command-line intervention, 
e.g. "fw_devlink=on" or "deferred_probe_timeout=3600" (with modules 
enabled for the latter to take full effect), but I'm wary of the 
potential for future config options to control those behaviours by default.

Robin.

> Thank you!
> 
>   -- Sergiy