[evandrofisico]

The "micro" in microvms is less about size and more about resources. A typical virtual machine under Xen or KVM (para)virtualizes a lot of hardware and emulates a lot of devices, so that the operating system sees it as a normal machine.

The microVM emulates the minimal possible set of devices needed to run, such as disks and network devices, and in the specific case of firecracker, through the use of the virtio model. So it can theoretically use huge amounts of memory of a large vCPU count and still be a microvm.