[PATCH 3/3] nodedev: add parent_addr to mdev nodedev dumpxml

[Boris Fiuczynski]

On 2/4/22 6:10 PM, Jonathon Jongsma wrote:
> On 2/4/22 9:32 AM, Boris Fiuczynski wrote:
>> As the parent address is part of the mdev nodedev name lets expose the
>> internally available parent address in the XML.
> 
> What is the issue that you're trying to solve here? The mdev xml already 
> has a reference to the name of the parent device. So presumably you can 
> look up the parent nodedev by name and then find its address, no? This 
> seems like you're duplicating parent information in the child. Is it 
> just for convenience?
> 
> Jonathon
> 

Actually it is not convenience. It is possible that an mdev definition 
exists and the parent device does not, e.g. the device driver has not 
been loaded or no longer is loaded and therefore the parent device might 
not/no longer exist or simply the parent device does not (for whatever 
reason) exist on the system at all.
The reason to extend the mdev nodedev object names with the parent 
device address was to make it unique. At the same time nodedev object 
names are supposed to be treated as arbitrary strings.
It is possible to retrieve the UUID but without the parent address or by 
looking at the nodedev object name and interpreting its last digits the 
information is not unique enough to find the related mdevctl definition.
I guess that for correlation reasons it is stored internally on the 
nodedev mdev objects.

-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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