The maxMem field of the virDomainInfo structure is given in bytes
instead of Kbytes when the domain is 0 (Domain-0). With others domains,
the value of maxMem is correct.
Exemple with virsh:
On a system with 4 GB memory, virsh reports:
# virsh dominfo 0
...
Max memory: 4294967292 kB
With the same libvirt version 0.1.9 but with an older Xen (not 3.0.3),
the maxMem value of Domain-0 is correct.