libvdsk - Adding support for the VMDK images

Lately, bhyve, the hypervisor embedded in the FreeBSD operating system, has known an increase in popularity. Therefore, it needs new features extensions of current libraries. As a powerful hypervisor, it should have support for many file formats. Moreover, it should be able to interact with virtual disk images that are created by other hypervisors. However, by default, it only supports raw file images which cannot be used for advanced functionalities such as disk checkpointing. The checkpointing mechanism is also important for the implementation of a virtual machine checkpointing mechanism for bhyve and that cannot be achieved using RAW disk images. To use multiple types of file images, it can use the libvdsk library that, besides RAW images, offers support for QCOW2 images too. This article proposes a solution for extending the functionality of the libvdsk library, integrating VMDK images, an image formats owned by VMware.