The nodes running virtual machine instances are commonly referred to as Compute nodes. Nova Compute nodes are running the nova-compute service, which manages the hypervisor it runs on via a hypervisor driver. A Nova-compute service passes commands to the local hypervisor via the driver to spawn or destroy virtual machine instances. The default and most commonly selected hypervisor with OpenStack is KVM; it requires virtualization hardware support by a CPU. CPUs with native support for KVM can be identified by VT-d (
vmx flag) with Intel CPUs and AMD-v (
svm flag) with AMD CPUs.
All supported hypervisors are listed in the OpenStack Wiki page https://wiki.openstack.org/wiki/HypervisorSupportMatrix.