Как увеличить количество ядер гостя KVM?

<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<name>one-94</name>
<cputune>
<shares>1024</shares>
</cputune>
<memory>8388608</memory>
<os>
<type arch='x86_64'>hvm</type>
</os>
<devices>
<emulator><![CDATA[/usr/bin/qemu-system-x86_64]]></emulator>
<disk type='file' device='disk'>
<source file='/var/lib/one//datastores/102/94/disk.0'/>
<target dev='vda'/>
<boot order='1'/>
<driver name='qemu' type='qcow2' cache='writeback'/>
</disk>
<disk type='file' device='cdrom'>
<source file='/var/lib/one//datastores/102/94/disk.1'/>
<target dev='hda'/>
<readonly/>
<driver name='qemu' type='raw'/>
</disk>
<interface type='bridge'>
<source bridge='br0'/>
<mac address='02:00:c0:a8:00:64'/>
<target dev='one-94-0'/>
</interface>
<graphics type='vnc' listen='0.0.0.0' port='5994'/>
</devices>
<features>
<pae/>
<acpi/>
<apic/>
</features>
<cpu mode='host-model'><topology sockets='1' cores='1' threads='1'/><model fallback='allow'/></cpu>
<metadata>
<system_datastore><![CDATA[/var/lib/one//datastores/102/94]]> </system_datastore>
</metadata>
</domain>