Re: [PATCH RFCv3 8/9] s390x: implement virtio-mem-ccw

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 27 Jul 2020 12:02:07 +0200
David Hildenbrand <david@redhat.com> wrote:

> On 27.07.20 11:58, Cornelia Huck wrote:
> > On Fri, 24 Jul 2020 16:37:49 +0200
> > David Hildenbrand <david@redhat.com> wrote:
> >   
> >> Add a proper CCW proxy device, similar to the PCI variant.
> >>
> >> Signed-off-by: David Hildenbrand <david@redhat.com>
> >> ---
> >>  hw/s390x/virtio-ccw-mem.c | 167 ++++++++++++++++++++++++++++++++++++++
> >>  hw/s390x/virtio-ccw.h     |  13 +++
> >>  2 files changed, 180 insertions(+)
> >>  create mode 100644 hw/s390x/virtio-ccw-mem.c  
> > 
> > What happens on an old machine type -- I guess the device is just
> > useless?  
> 
> Trying to plug will fail in the pre_plug stage via
> 
> hw/mem/memory-device.c:memory_device_pre_plug()->memory_device_get_free_addr()
> 
> with "memory devices (e.g. for memory hotplug) are not supported by the
> machine"
> 
> whereby never machines where "maxmem" was not properly specified will
> result in
> 
> "memory devices (e.g. for memory hotplug) are not enabled, please
> specify the maxmem option"
> 

Ah, sounds good :)