Re: [Qemu-devel] Re: [PATCH v2 9/9] Add -kvm option

[Gleb Natapov]

On Thu, Oct 08, 2009 at 04:30:17PM +0200, Avi Kivity wrote:
> On 10/08/2009 04:23 PM, Anthony Liguori wrote:
> >>>What I'd like to see in the interim is a kvm specific machine
> >>>type that's defaulted to if kvm is enabled.  I think this
> >>>would be useful not only for enabling things like in-kernel
> >>>apic, but also for selecting a default cpu model.
> >>
> >>We should make a distinction between guest-visible changes and
> >>accelerators like kvm-irqchip and vhost.
> >
> >They are different device models that happen to implement the same
> >guest-visible device.
> 
> I think this separation is artificial.  From both the guest's view
> and the user's view, there's no difference between qemu ioapic and
> kvm ioapic (modulo bugs).  To me this indicates they're the same
> device.
> 
Same device but different implementation. The only two things that are
used from qemu apic implementation with in-kernel apic are migration and
reset. Both depends on implementation. Reusing code will require us to
keep implementation in sync. This reuse is a constant source of bugs
BTW.

> We'll have the same problem with vhost-net, only there the
> duplication will be much greater if we split the implementation.
> 
> -- 
> error compiling committee.c: too many arguments to function
> 
> 

--
                        Gleb.