Comment 20 for bug 1828495

@rafaeldtinoco: I found some forther more ugly detail for the stepping change from 5 to 6.
Qemu 3.1 as in Disco had Cascade lake with the stepping 5.
So for Disco the SRU will change the definition.
Which is different to Bionic/Cosmic where we can say "our Cascade definition will just always have been 6" since it didn't exist before the SRU

You'll spot that when you start to create the branch for disco
Note: cosmic has none of the types

Due to that for those users who have set up guests to use "Cascadelake-Server" the SRU on Disco (or the respective cloud archive) will make them need to restart the guest before they can migrate it to a system with the updates applied.

For bionic/cosmic users things will be fine as they have nothing->stepping6
And Eoan will be released with stepping 6

I think that is a drawback, but a tradeoff that we will have to make for the overall gain for much more users. But we need to declare that in the regression considerations of the bug when pushing the SRU.

@rafaeldtinoco: when you have branches and PPAs for Disco as well, could you spawn a Cascadelake-Server guest on a node without the upgrade and then migrate to a note with the upgrade?
I expect an issue, but we should know how exactly it looks.
Once we do we will add that to the SRU template in the description.