Re: [libvirt] [RFC 00/28] s390x CPU models: exposing features

On Wed, Jun 22, 2016 at 09:34:49 +0200, David Hildenbrand wrote: > I think the coffee didn't do its work already :) . I wanted to write that we can > _with_ this additional query. Meaning the involved overhead would be ok - in my > opinion for s390x. > > What we could do to avoid one compare operation would be: > > a) Expand the host model > b) Expand the target model (because on s390x we could have migration unsafe > model) > c) Work with the runnability information returned via query-cpu-definitions > > But as we have to do b) either way on s390x, we can directly do a compare > operation. (which makes implementation a lot simpler, because libvirt then > doesn't have to deal with any feature/model names). But why do you even need to do any comparison? Isn't it possible to let QEMU do it when a domain starts? The thing is we should avoid doing completely different things on each architecture.