1. A method for providing a cloud environment for provisioning a guest virtual machine instance, wherein the method comprises: selecting at least one machine from a collection of machines as a management node, wherein the at least one machine includes a hypervisor enabled with nested virtualization capability; deploying a plurality of cloud managers on each management node; selecting at least one machine from the collection of machines as a host node; to deploying a plurality of level two hypervisors on each host node; forming a plurality of virtual clouds, wherein each virtual cloud contains at least one of the plurality of cloud managers and one of the plurality of level two hypervisors; and provisioning, via the at least one cloud manager, at least one guest virtual machine instance on top of the at least one level two hypervisors; wherein at least one of the steps is carried out by a computer device.