[PATCH libvirt v1 0/6] Fix ZPCI address auto-generation on s390

[Boris Fiuczynski]

On 5/14/20 3:59 PM, Andrea Bolognani wrote:
> On Thu, 2020-05-14 at 15:34 +0200, Boris Fiuczynski wrote:
>> On 5/14/20 10:37 AM, Daniel P. Berrangé wrote:
>>> I don't see this existing behaviour as confusing. It looks like mostly
>>> being a docs ommission about auto-allocation taking place.
>>
>> Maybe I am repeating myself but I find e.g the below example confusing
>> if I take into consideration that uid=0 is NOT a valid value and fid is
>> a valid value. Please note that the valid fid is dislocated from its
>> original device!
>>
>> Specify this in the domain:
>>      pcidev1: uid='0x0000' fid='0x00000000'
>>      pcidev2: uid='0x0000'
>> Results in a defined domain:
>>      pcidev1: uid='0x0002' fid='0x00000001'
>>      pcidev2: uid='0x0001' fid='0x00000000'
>>
>> If the user would be tying to fix the dislocating fid... one would very
>> likely try this:
>> Specify this in the domain:
>>      pcidev1: uid='0x0000' fid='0x00000000'
>>      pcidev2: uid='0x0000' fid='0x00000001'
>> Result:
>> error: Failed to define domain from mini-pcis.xml
>> error: XML error: Invalid PCI address uid='0x0000', must be > 0x0000 and
>> <= 0xffff
> 
> And partial assignments, which one might reasonably expect to work,
> actually don't:
> 
>    fid=0 -> interpreted the same as no information provided
>          -> valid address but probably not fid=0
> 
>    fid=x -> interpreted as uid=0 fid=x
>          -> invalid address because uid=0 is invalid
> 
> Plus, if you have two devices:
> 
>    uid=1, uid=2 -> interpreted as uid=1 fid=0, uid=2 fid=0
>                 -> invalid addresses because of duplicated fid
> 
> Dan, please go through the entire thread and look at the other
> examples that Shalini, Boris and I have provided: I think you'll
> see why I feel like it's hard to argue that the current behavior can
> be considered reasonable from the user's point of view.
> 

If I do not misinterpret Dan's last mail he agrees that specifying uid=0 
should be considered as error.
How do we proceed from here? Shalini series still can be applied on 
master cleanly. Do you want her to resend the series anyway?

-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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