[libvirt] [PATCH 6/4] qemu: address: Remove QEMU_CAPS_DEVICE usage

Cole Robinson crobinso at redhat.com
Wed May 18 18:37:36 UTC 2016

On 05/18/2016 10:59 AM, Andrea Bolognani wrote:
> On Wed, 2016-05-18 at 09:58 -0400, Laine Stump wrote:
>> On 05/18/2016 07:53 AM, Cole Robinson wrote:
>>> Kind of. Prior to patch #2, the test suite output was correct (no addresses),
>>> it's what we were returning via domxml-from-native. After patch #2, the test
>>> suite output was wrong for all real world usage; it didn't change because it
>>> was only hitting a !QEMU_CAPS_DEVICE code path
>>> So the potentially contentious bit is that patch #2 changes domxml-from-native
>>> output to contain addresses, however that's exactly the same result that will
>>> happen when the XML would eventually be defined anyways, so it's effectively
>>> the same result as pre-patch #2 anyways. If we think of domxml-from-native as
>>> telling the user 'this is exactly what libvirt thinks that command line is'
>>> then we are now giving more accurate results
>>> Let me know if that still warrants the ACK
>> My opinion is that this is a change for the better. While it is true 
>> that this could lead to XML that potentially shows different PCI 
>> addresses than what would have been auto-assigned by qemu when presented 
>> with the original commandline, it *is* showing the addresses that would 
>> be auto-allocated by libvirt if you had fed the "un-addressified" XML to 
>> libvirt - so at least the user will get a warning rather than being 
>> surprised at runtime. And it's not as if the output of 
>> domxml-from-native has ever produced anything even close to the correct 
>> XML in any real world situation. (dreadkopp in public #virt pastebin'ed 
>> an example last night - 90% of it was translated directly into 
>> <qemu:arg> elements).
> After reading Cole's explanation, I tend to agree.
> So I guess we can go ahead and merge this, as well as 5/4 :)

Thanks pushed now with your suggested changes, except the bits I just mailed about

- Cole

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