To allow compatibility with older QEMU PCI device slot assignment
it is necessary to explicitly track the balloon device in the
XML. This introduces a new device
<memballoon model='virtio|xen'/>
It can also have a PCI address, auto-assigned if necessary.
The memballoon will be automatically added to all Xen and QEMU
guests by default.
* docs/schemas/domain.rng: Add <memballoon> element
* src/conf/domain_conf.c, src/conf/domain_conf.h: parsing
and formatting for memballoon device. Always add a memory
balloon device to Xen/QEMU if none exists in XML
* src/libvirt_private.syms: Export memballoon model APIs
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Honour the
PCI device address in memory balloon device
* tests/*: Update to test new functionality
The current syntax uses a pair of args
-net nic,macaddr=52:54:00:56:6c:55,vlan=3,model=pcnet,name=pcnet.0
-net user,vlan=3,name=user.0
The new syntax does not need the vlan craziness anymore, and
so has a simplified pair of args
-netdev user,id=user.0
-device pcnet,netdev=user.0,id=pcnet.0,mac=52:54:00:56:6c:55,addr=<PCI SLOT>
