Re: [Qemu-devel] [RFC PATCH 1/1] s390x/css: unresrict cssids

[Halil Pasic]

On 11/27/2017 03:03 PM, Christian Borntraeger wrote:
> 
> 
> On 11/27/2017 02:19 PM, Cornelia Huck wrote:
>> On Mon, 27 Nov 2017 14:11:57 +0100
>> Halil Pasic <address@hidden> wrote:
>>
>>> On 11/27/2017 01:56 PM, Cornelia Huck wrote:
>>>> On Fri, 24 Nov 2017 17:39:04 +0100
>>>> Halil Pasic <address@hidden> wrote:
>>>>   
>>>>> On 11/24/2017 05:15 PM, Cornelia Huck wrote:  
>>
>>>>>> (Unless we simply make this a "default cssid" prop after all - then it
>>>>>> would be more than just a simple indication for libvirt...)
>>>>>>     
>>>>>
>>>>> We are now talking about the "cssid-unrestricted" property. The default
>>>>> cssid is not something I would like to do any time soon.  
>>>>
>>>> What's so bad about this? As said above, I think it would be much more
>>>> useful. If libvirt can detect r/o vs. r/w for properties, we can simply
>>>> start out with a r/o variant now...
>>>>   
>>>
>>> I'm not sure I understand you. Are you proposing the following:
>>> Drop the restriction, but don't indicate this via a read only
>>> "cssid-unrestricted" device property but via a "default-css"
>>> read only machine property.
>>>
>>> Libvirt then should know that if "default-css" is present then
>>> we don't have this virtual into 0xfe and non virtual into 0xfd
>>> restriction any more.
>>
>> Yes.
> 
> Unless we implement the ability to set the default css _NOW_, I would
> prefer to not couple different things (ability to change default-css
> and abiltity to move devices around). Otherwise we might need to change
> things again if we find out that our plan does not work out.
> 
> So what about having
> - a cssid-unrestricted machine property that shows that devices can move 
> around
> - later a default-css machine property when we actually implement that
> 
> ?
> 

I can -- compromise and -- live with that. I'm still not convinced
that having the property at the machines is better. But I don't think,
I can convince Connie that having it at the devices is better. I would
like to get this done.

> Christian
> 
>