Problem with xen config

[Jim Fehlig]

On 8/10/20 10:55 AM, Laine Stump wrote:
> On 8/10/20 4:38 AM, Christoph wrote:
>>>>
>>>> xen_platform_pci=1
>>>
>>> This setting is not supported in the libvirt libxl driver, but AFAICT
>>> libxl sets the default to 'true' for HVM guests.
>>>
>>>> pci_msitranslate=1
>>>
>>> This is also not supported in libvirt and unfortunately defaults to
>>> 'false'.
>>>
>>>> pci_permissive = 1
>>>
>>> Patches have been submitted for this setting but so far there has not
>>> been agreement on the schema change
>>>
>>> https://www.redhat.com/archives/libvir-list/2020-April/msg01230.html
> 
> Hmm, so I see that discussion stalled after I asked a few questions, and then 
> you (Jim) made a few suggestions about where the attribute should go and what it 
> should be named. (note for newcomers - the original patch messages linked above 
> were at the end of April, but the replies discussing them were in May, so they 
> don't show up directly in the primitive mailman archive page for the original 
> messages; to see them you need to go here:
> 
> https://www.redhat.com/archives/libvir-list/2020-May/thread.html
> 
> then search for "permissive" in the page - this will show you followups to all 
> the original patch mails.
> 
> 
> I'm not sure who should be pushing the discussion/decision - I've already said 
> my piece, and would be just as happy with anything as long as it doesn't 
> interfere with usage for qemu. Maybe someone else has a stronger opinion.

I just posted a V3 that supports a 'writeFiltering' attribute on the <source> 
element

https://www.redhat.com/archives/libvir-list/2020-August/msg00465.html

E.g.

     <hostdev mode='subsystem' type='pci'>
       ...
       <source writeFiltering='no'>
         <address .../>
       </source>
     </hostdev>

However, after reading your reply again, I realize I forgot to add the check you 
requested in the qemu driver's post-parse validation logic. I can do that in V4 
but I'd like to get some feedback on the modeling approach first.

Regards,
Jim