Re: [Qemu-devel] [PATCH 5/5] hw: arm_gic_kvm: Add KVM VGIC save/restore logic

[Peter Maydell]

On 21 September 2013 06:46, Christoffer Dall
<address@hidden> wrote:
> On Sat, Sep 21, 2013 at 06:22:23AM +0900, Peter Maydell wrote:
>>  *) for getting TCG<->KVM and KVM-with-non-host-CPU cases
>> right we need to do translation anyway, or at least think about it.
>
> Why? Wouldn't we always only support the case where QEMU emulates the
> same model as KVM in the first case, and the kernel should behave the
> same and export the same state if you ask for a specific target no
> matter what the underlying hardware is, no?

If the kernel has to be able to do translation of the state, why
not make its life easier by having it only need to do one thing
(host h/w format -> whatever standard format we pick)
rather than lots and lots of things
(host CPU X h/w format -> format for supported guest CPU A,
 host CPU X h/w format -> format for supported guest CPU B,
 host CPU Y h/w format -> format for guest CPU A,
 host CPU Y h/w format -> format for guest CPU B,
 etc etc etc)

? That's basically a cross product over every CPU we
support.

-- PMM