numa hook
=========
add numa support for domain xml:

<numatune>
    <memory mode="strict" nodeset="1-4,^3"/>
</numatune>

memory=interleave|strict|preferred

numaset="1" (use one NUMA node)
numaset="1-4" (use 1-4 NUMA nodes)
numaset="^3" (don't use NUMA node 3)
numaset="1-4,^3,6" (or combinations)

numa=strict:1-4
numa: numa=strict:5
    add NUMA support can be [interleave|strict|preferred] with 5 nodes,
    nodes can be "1" (use one NUMA node) "1-4" (use 1-4 NUMA nodes)
    "^3" (don't use NUMA node 3) "1-4,^3,6" (or combinations)
