Re: [PATCH V4 6/6] dt-bindings: xen: Clarify "reg" purpose

[Oleksandr <olekstysh@xxxxxxxxx>]

On 10.12.21 11:09, Julien Grall wrote:
> Hi Oleksandr,

Hi Julien


> On 09/12/2021 20:05, Oleksandr Tyshchenko wrote:
> > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> >
> > Xen on Arm has gained new support recently to calculate and report
> > extended regions (unused address space) safe to use for external
> > mappings. These regions are reported via "reg" property under
> > "hypervisor" node in the guest device-tree. As region 0 is reserved
> > for grant table space (always present), the indexes for extended
> > regions are 1...N.
> >
> > No device-tree bindings update is needed (except clarifying the text)
> > as guest infers the presence of extended regions from the number
> > of regions in "reg" property.
> >
> > While at it, remove the following sentence:
> > "This property is unnecessary when booting Dom0 using ACPI."
> > for "reg" and "interrupts" properties as the initialization is not
> > done via device-tree "hypervisor" node in that case anyway.
> You sent a similar patch for Xen and have already commented there [1] 
> . In short, the OS will be using the node to discover whether it is 
> running on Xen for both ACPI and DT. The hypervisor node also contain 
> the UEFI information for dom0.
I agree with your comments. The sentence should remain in this case. 
Thank you for pointing this out.

> Cheers,
>
> [1] 
> https://lore.kernel.org/xen-devel/9602b019-6c20-cdc7-23f3-9e4f8fd720f6@xxxxxxx/T/#t
--
Regards,

Oleksandr Tyshchenko