Re: [libvirt] [RFC] qemu: Redesigning guest CPU configuration

On Thu, Jun 18, 2015 at 14:41:17 +0100, Daniel P. Berrange wrote: > > So either we need to define all existing CPU models in all their > > variants used for various machine types and have a mapping between > > (model without a version, machine type) to a specific version of the > > model (which may be quite hard) or we need to be able to distinguish > > between an existing domain and a new domain with no CPU model version. > > While host-model and host-passthrough CPU modes are easy because they > > are designed to change everytime a domain starts (which means we don't > > need to be able to distinguish between existing and new domains), custom > > CPU mode are tricky. Currently, the only at least a bit reasonable thing > > which came to my mind is to have a new CPU mode, but it still seems > > awkward so please share your ideas if you have any. > > Introducing a new CPU mode feels pretty unpleasant to me. > > Although it will certainly be tedious work, getting details of all the > CPU variants for historical machine types should be doable I think. Yeah, I also prefer this variant but I was kind of hoping someone would come up with a bright idea which would safe me from all the work :-P