[libvirt-users] cannot set maxMemory

Hi all, I'm testing the memory hotplugging on devstack (ocata version). According to the article in https://medium.com/@juergen_thomann/memory-hotplug-with-qemu-kvm-and-libv... , I'm trying to create a virtual machine by setting <maxMemory>. However, I've got an error message in libvirt log as below. 2017-07-20 20:33:21.175+0000: 529: error : virDomainDefCheckUnsupportedMemoryHotplug:1192 : unsupported configuration: memory hotplug tunables <maxMemory> are not supported by this hypervisor driver virt-aa-helper: error: could not parse XML virt-aa-helper: error: could not get VM definition I'm using qemu hypervisor (2.8), and libvirt (2.5.0). As I know, these qemu, libvirt versions support hotplugging memory. Below is the xml file I used to create a virtual machine by using 'virsh create test.xml' command. <domain type='qemu'> <name>QEmu-fedora-i686</name> <uuid>c7a5fdbd-cdaf-9455-926a-d65c16db1809</uuid> <maxMemory slots='4' unit='KiB'>2097152</maxMemory> <memory>219200</memory> <currentMemory>219200</currentMemory> <vcpu>2</vcpu> <cpu> <numa> <cell id="0" cpus="0" memory="2097152" unit="KiB"/> </numa> </cpu> <driver name="qemu" type="qcow2" cache="none"/> <os> <type arch='i686' machine='pc'>hvm</type> <boot dev='cdrom'/> </os> <devices> <emulator>/usr/bin/qemu-system-ppc</emulator> <disk type='file' device='cdrom'> <source file='/home/user/boot.iso'/> <target dev='hdc'/> <readonly/> </disk> <disk type='file' device='disk'> <source file='/home/user/fedora.img'/> <target dev='hda'/> </disk> <interface type='network'> <source network='default'/> </interface> </devices> </domain> Does anyone know the reason? Thanks, Youngbin