Re: [XEN][PATCH 0/8] xen/arm64: make aarch32 support optional

[Julien Grall <julien@xen.org>]

Hi,

On 23/07/2025 12:48, Grygorii Strashko wrote:
> 
> 
> On 23.07.25 13:54, Orzel, Michal wrote:
>>
>>
>> On 23/07/2025 10:06, Julien Grall wrote:
>>>
>>>
>>> On 23/07/2025 08:58, Grygorii Strashko wrote:
>>>> From: Grygorii Strashko <grygorii_strashko@epam.com>
>>>>
>>>> Hi,
>>>
>>> Hi Grygorii,
>>>
>>>> Now Arm64 AArch32 guest support is always enabled and built-in while 
>>>> not
>>>> all Arm64 platforms supports AArch32 or this support might not be 
>>>> needed.
>>>
>>> I am not entirely sure I like the proliferation of using CONFIG_* for
>>> every single feature. This makes the testing a bit more complicated.
>>>
>>> Can you clarify what the goal with this patch?
>> AArch32 is used quite rarely in embedded systems. Also, in Armv9A it 
>> might only
>> be implemented at EL0 if at all. When focusing on safety 
>> certification, AArch32
>> related code in Xen leaves a gap in terms of coverage that cannot 
>> really be
>> justified in words. This leaves us with two options: either support it 
>> (lots of
>> additional testing, requirements and documents would be needed) or 
>> compile it out.
> 
> FYI. bloat-o-meter report for this series with CONFIG_ARM64_AARCH32=n, 
> CONFIG_EXPERT=y

Thanks for sharing the bloat-o-meter. But I don't think the result below 
warrant a new config. The reason provided by Michal is a better reason 
as the impact on safety certification is more significant.

Cheers,

-- 
Julien Grall