On 3 July 2015 at 09:28, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 03/07/15 09:12, Peter Maydell wrote: >> I would still like to see the proponents of this patch say >> what their model is for userspace support of cross-host migration, >> if we're abandoning the model the current API envisages. > > I thought we had discussed this above, and don't really see this as a > departure from the current model: > > - "-cpu host" results in "GENERIC" being used: VM can only be migrated > to the exact same HW (no cross-host migration). MIDR should probably > become RO. > - "-cpu host" results in "A57" (for example): VM can be migrated to a > variety of A57 platforms, and allow for some fuzzing on the revision (or > accept any revision). > - "-cpu a57" forces an A57 model to be emulated, always. It is always > possible to migrate such a VM on any host. > > I think only the first point is new, but the last two are what we have > (or what we should have). Right, but the implicit idea of this GENERIC patch seems to be that new host CPU types don't get their own KVM_ARM_TARGET_* constant, and are thus forever unable to do cross-host migration. It's not clear to me why we'd want to have new CPUs be second class citizens like that. -- PMM -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
