[libvirt] [RFC] memory settings interface for containers

[Nikolay Shirokovskiy]

Hi, everyone.

I plan to add means to configure vz containers memory setting and have trouble
getting it done thru libvirt interface. Looks like current interface fits good
for vm memory managment but its not clear how to use it with containers. First
let's take aside memory hotplugging which is obviously not suitable for
containers. Then memory interface is represented by 2 parameters: total_memory
and cur_balloon. For VMs total_memory can't be changed at runtime, cur_ballon
can't be greater than total_memory. But for containers memory model is
different. We have only one parameter and it can be changed for running 
domains. So question is how to map this model to existing interface (it is
unlikely to have a new interface for this case). I plan to make both parameters
to have same meaning and be equal for containers and update virsh, API and xml
model documentation accordingly.

I'd be happy to hear core developers opinions on this topic.