Re: [Qemu-devel] [PATCH 1/6] s390x/virtio-ccw: enable has_dynamic_sysbus

[Alexander Graf]

On 04/22/2015 10:25 AM, Cornelia Huck wrote:
> On Tue, 21 Apr 2015 21:06:42 +0200
> Alexander Graf <address@hidden> wrote:
>
> > On 04/17/2015 09:52 AM, Cornelia Huck wrote:
> > > From: Xu Wang <address@hidden>
> > >
> > > We have to enable this flag to support dynamically adding devices to the
> > > sysbus. This change is needed for the the upcoming diag288 watchdog.
> > s390 doesn't have a "sysbus" per se. Please create a new bus type.
> So what's wrong with the sysbus? I don't see why we should be different
> than everyone else.

The idea behind sysbus is that you have MMIO, PIO and IRQ pins 
connecting to a PIC. It provides a lot of infrastructure for those 
interfaces. S390 doesn't use any of them and instead wants registration 
on "diag" interfaces for example which I'd put on the same layer as PIO 
or MMIO registration.


Alex