Re: [XEN PATCH] xen/arm: Relax GIC version check

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

Julien Grall writes ("Re: [XEN PATCH] xen/arm: Relax GIC version check"):
> On 20/01/2021 11:26, Vladimir Murzin wrote:
> > Supported values are
> > 
> > 0b0000 GIC CPU interface system registers not implemented.
> > 
> > 0b0001 System register interface to versions 3.0 and 4.0 of the GIC
> >         CPU interface is supported.
> > 
> > 0b0011 System register interface to version 4.1 of the GIC CPU
> >         interface is supported.
> > 
> > 4.1 is still backward compatible with 4.0/3.0, moreover ARM ARM
> > guarantees that future versions of the GIC CPU interface retain
> > backwards compatible.
> > 
> > Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
> 
> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
> 
> @Ian: I would like your put as the RM for 4.15.
> 
> Technically, it could be consider as a new "feature" because Xen would 
> fail to boot on such HW.
> 
> However, I think the change is small enough and doesn't introduce risk 
> on existing supported HW.
> 
> Therefore, I would like to merge it for 4.15. @Ian does it sounds good 
> to you?

Thank you for this analysis.  I think it does need a freeze
exception.  But your argument is convincing, so

Release-Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>