I was able to gather libvirt XMLs from both Newton and Ocata Instances, see attached 

sfeole@BSG-75:~$ diff xmlocata xmlnewton 
1,2c1,2
< 
< main type='kvm' id='1'>
---
> ubuntu@lundmark:/var/lib/nova/instances/358596e4-135d-461d-a514-84116440014c$ sudo virsh dumpxml instance-00000001
> <domain type='kvm' id='1'>
4c4
<   <uuid>7c0dcd78-d6b4-4575-a882-ee5d29c64fe0</uuid>
---
>   <uuid>358596e4-135d-461d-a514-84116440014c</uuid>
7,9c7,9
<       <nova:package version="15.0.6"/>
<       <nova:name>sfeole14</nova:name>
<       <nova:creationTime>2017-10-05 00:58:15</nova:creationTime>
---
>       <nova:package version="14.0.8"/>
>       <nova:name>sfeole-newton</nova:name>
>       <nova:creationTime>2017-10-05 01:40:39</nova:creationTime>
18,19c18,19
<         <nova:user uuid="d9f92a61c37948d9a29b8cc37e1bca05">admin</nova:user>
<         <nova:project uuid="701441267bd148d3842f1696530b1c92">admin</nova:project>
---
>         <nova:user uuid="12d13712253141ab845b89406507cd6c">admin</nova:user>
>         <nova:project uuid="8b8fcaf183954f45b3eb15b27c52ec94">admin</nova:project>
21c21
<       <nova:root type="image" uuid="f329117f-5da2-4d61-8341-89a969bf00e7"/>
---
>       <nova:root type="image" uuid="fcdf7c26-4238-4594-b8ee-fd59f601fdcb"/>
34c34
<     <type arch='aarch64' machine='virt-2.8'>hvm</type>
---
>     <type arch='aarch64' machine='virt'>hvm</type>
58c58
<       <source file='/var/lib/nova/instances/7c0dcd78-d6b4-4575-a882-ee5d29c64fe0/disk'/>
---
>       <source file='/var/lib/nova/instances/358596e4-135d-461d-a514-84116440014c/disk'/>
61c61
<         <source file='/var/lib/nova/instances/_base/035458feead7f83be80ed020442ebf815a4067ea'/>
---
>         <source file='/var/lib/nova/instances/_base/ab7429e8558ea27fb54f70eb92fbd0c1c07dd595'/>
70c70
<       <source file='/var/lib/nova/instances/7c0dcd78-d6b4-4575-a882-ee5d29c64fe0/disk.eph0'/>
---
>       <source file='/var/lib/nova/instances/358596e4-135d-461d-a514-84116440014c/disk.eph0'/>
82a83,93
>     <controller type='pci' index='1' model='dmi-to-pci-bridge'>
>       <model name='i82801b11-bridge'/>
>       <alias name='pci.1'/>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
>     </controller>
>     <controller type='pci' index='2' model='pci-bridge'>
>       <model name='pci-bridge'/>
>       <target chassisNr='2'/>
>       <alias name='pci.2'/>
>       <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'/>
>     </controller>
84,86c95,97
<       <mac address='fa:16:3e:a6:4b:d4'/>
<       <source bridge='qbra7012530-32'/>
<       <target dev='tapa7012530-32'/>
---
>       <mac address='fa:16:3e:8e:fc:48'/>
>       <source bridge='qbrb5d335fc-46'/>
>       <target dev='tapb5d335fc-46'/>
92c103
<       <source path='/var/lib/nova/instances/7c0dcd78-d6b4-4575-a882-ee5d29c64fe0/console.log'/>
---
>       <source path='/var/lib/nova/instances/358596e4-135d-461d-a514-84116440014c/console.log'/>
95a107,111
>     <serial type='pty'>
>       <source path='/dev/pts/3'/>
>       <target port='1'/>
>       <alias name='serial1'/>
>     </serial>
97c113
<       <source path='/var/lib/nova/instances/7c0dcd78-d6b4-4575-a882-ee5d29c64fe0/console.log'/>
---
>       <source path='/var/lib/nova/instances/358596e4-135d-461d-a514-84116440014c/console.log'/>
108,113c124,125
<     <label>libvirt-7c0dcd78-d6b4-4575-a882-ee5d29c64fe0</label>
<     <imagelabel>libvirt-7c0dcd78-d6b4-4575-a882-ee5d29c64fe0</imagelabel>
<   </seclabel>
<   <seclabel type='dynamic' model='dac' relabel='yes'>
<     <label>+64055:+117</label>
<     <imagelabel>+64055:+117</imagelabel>
---
>     <label>libvirt-358596e4-135d-461d-a514-84116440014c</label>
>     <imagelabel>libvirt-358596e4-135d-461d-a514-84116440014c</imagelabel>
sfeole@BSG-75:~$