Re: [PATCH v2 for 4.5] xen/arm: Add support for GICv3 for domU

[Julien Grall <julien.grall@linaro.org>]

On 05/11/2014 11:22, Ian Campbell wrote:
>>>
>>>> +         * hardware GIC. Only the value XEN_DOMCTL_CONFIG_GIC_DEFAULT
>>>> +         * is allowed. The DOMCTL will return the actual version of the
>>>> +         * GIC.
>>>> +         */
>>>> +        if ( domctl->u.configuredomain.gic_version != XEN_DOMCTL_CONFIG_GIC_DEFAULT )
>>>> +            return -EOPNOTSUPP;
>>
>>> I'm also tempted to suggest that we should accept gic_version == the hw
>>> value, i.e. by moping the switch below up and including
>>>           && domctl->u.configuredomain.gic_version != gic_version
>>> in the condition.
>>
>> I consider that explicitly asking for a version of the GIC in Xen 4.5 is
>> invalid. The user should only be able to use the default GIC.
>>
>> As the DOMCTL is not set in stone,
>
> I disagree with your reasoning, but given this I'm not inclined to keep
> arguing about it.

TBH, I should just ignore the value for Xen 4.5 and let the hypervisor 
return the version of the vGIC.

The check was just here to explicitly show that we don't support 
anything else in DOM0.

Regards,

-- 
Julien Grall