[PATCH] arm64/kvm: Add generic v8 KVM target

Peter Maydell peter.maydell at linaro.org
Fri Jul 3 02:34:38 PDT 2015

On 3 July 2015 at 09:28, Marc Zyngier <marc.zyngier at arm.com> 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

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