[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 1/7] tools: ARM: vGICv3: avoid inserting optional DT properties

Hi Andre,

On 24/01/18 16:35, Andre Przywara wrote:
On 24/01/18 16:08, Julien Grall wrote:
(+ Tools maintainers)

Hi Andre,

On 24/01/18 14:35, Andre Przywara wrote:
When creating a GICv3 devicetree node, we currently insert the
redistributor-stride and #redistributor-regions properties, with fixed
values which are actually the architected ones. But those properties are
optional and only needed to cover for broken platforms, where the values
differ from the architected one. This will never be the case for the

I understand that the stride is defined by GICv3. But I don't think this
is true for the number of regions. Looking at the spec, multiple regions
seems to be allowed (see GICR_TYPER.Last). Did I miss anything?

Well, the spec does indeed not say anything about it, but the DT binding
description does:
- #redistributor-regions: The number of independent contiguous regions
   occupied by the redistributors. Required if more than one such
   region is present.

So we don't need it in our case, and in fact we don't implement
*anything* to actually give the toolstack a choice. So we should
consequently remove these lines, as they are pointless right now. Should
we ever need to implement support for multiple regions, bringing this
back is really our least concern.

I am not against this patch. However, the commit message should not induce that platform with more than 1 re-distributor regions are broken.

So I don't see anything which would prevent us to provide a guest memory map with multiple re-distributor regions.


Julien Grall

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.