Re: [Qemu-devel] [Qemu-ppc] [PATCH 03/12] pseries: Move XICS initialization before cpu initialization

[David Gibson]

On Tue, Nov 20, 2012 at 10:26:06AM +0100, Alexander Graf wrote:
> 
> On 19.11.2012, at 23:47, David Gibson wrote:
> 
> > On Tue, Nov 20, 2012 at 06:54:20AM +1100, Benjamin Herrenschmidt wrote:
> >> On Mon, 2012-11-19 at 17:22 +0100, Alexander Graf wrote:
> >>>> Currently, the pseries machine initializes the cpus, then the XICS
> >>>> interrupt controller.  However, to support the upcoming in-kernel XICS
> >>>> implementation we will need to initialize the irq controller before the
> >>>> vcpus.  This patch makes the necesssary rearrangement.  This means the
> >>>> xics init code can no longer auto-detect the number of cpus ("interrupt
> >>>> servers" in XICS terminology) and so we must pass that in explicitly from
> >>>> the platform code.
> >>> 
> >>> Does this still hold true with the new in-kernel interrupt controller 
> >>> workflow?
> >> 
> >> We need to look into this. The in-kernel ICPs will still certainly be
> >> created early along with the VCPUs, however we might be able to delay
> >> the creation of the qemu emulation when not using the former.
> > 
> > I'd really prefer not to have two different initialization orders in
> > qemu though.  I think we'll want the ICP initialization first for CPU
> > hotplug one day anyway.
> 
> I'd just leave this patch out until you have an implementation of
> the new in-kernel interrupt controller model as discussed during KVM
> Forum. If it still makes sense by then, we can always apply it along
> with it :). You most likely want to reshuffle code by then anyway,
> so this patch would just be needless churn.

Ok.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
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