Thanks alot for the review and feedback. As for host-passthrough cases, I have some other understandings,
if I understand correctly, what you mean is that if a vm uses host-passthrough, it can migrate to any other
host, since it asks for host-passthrough. In my point of view, I think in real cases, there are few different kinds
of ARM datacenter CPUs on the market, and there CPU capabilities are different, so one might create a vm on
hostA with feature1 and feature2 because it uses host-passthrough and hostA has these features. Now in your
definition(if I understand correctly) of host-passthrough and the current code(returns identical directly), this vm
can be migrated to hostB with only feature1, since there are no limitations. If one has some important application
that depends on feature2, the app will break as feature2 is not available on hostB. Considering this, I proposed
to add basic checks to compare CPU to limit the migration to only the same CPU models. And once the capability
of ARM driver is enhanced in QEMU or other related projects, we can make the compare API better.
And yes, the code referenced X86 and S390 driver, I have modified them to be workable with ARM and tested
the functions, I was also thinking that in the future there might be possibility that we can compare cpu features
so I kept the data compare case.
Thanks again for the feedback.