KVM memory & CPU allocation

Hi all,

I'm just trying to to learn my way around KVM and using virt-manager. I was just wondering - if I set Max Memory Allocation to 8192MB and Current Allocation to 2048MB for example, will the VM automatically take more memory if it needs it and release it when it's not needed? Same with CPU allocation - if i set max allocation to 8 virtual CPUs and current allocation to 2 ....

Thanks,
JB