<controller type='pci' index='0' model='pci-root'/>
is auto-added to pc* machine types.
Without this controller PCI bus 0 is not available and
no PCI addresses are assigned by default.
Since older libvirt supported PCI bus 0 even without
this controller, it is removed from the XML when migrating.
<vcpu> is not an optional node. The value for its 'placement'
actually always defaults to 'static' in the underlying codes.
(Even no 'cpuset' and 'placement' is specified, the domain
process will be pinned to all the available pCPUs).
Output is still in kibibytes, but input can now be in different
scales for ease of typing.
* src/conf/domain_conf.c (virDomainParseMemory): New helper.
(virDomainDefParseXML): Use it when parsing.
* docs/schemas/domaincommon.rng: Expand XML; rename memoryKBElement
to memoryElement and update callers.
* docs/formatdomain.html.in (elementsMemoryAllocation): Document
scaling.
* tests/qemuxml2argvdata/qemuxml2argv-memtune.xml: Adjust test.
* tests/qemuxml2xmltest.c: Likewise.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-memtune.xml: New file.
