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

[David Hildenbrand]

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"

-- 
Thanks,

David / dhildenb