Changes have been made to the VirtualBox virtualization system repository to incorporate support for the KVM hypervisor built into the Linux kernel instead of the specific VirtualBox kernel module (vboxdrv). The implementation, prepared by Oracle employees, is separate from the VirtualBox-KVM backend being developed by Cyberus Technology. Despite Oracle initiating work on the KVM backend several years ago, progress was hindered by a lack of engineering resources.
With the inclusion of commit 5cb05ca, the KVM backend is now functional for more modern guests, although older and less common operating systems like MS-DOS are not yet supported or tested. If VirtualBox is unable to access its native kernel drivers, it will utilize KVM as an alternative. Compatibility between stored states in the native hypervisor and KVM is crucial. Presently, there are no test builds available, and the code can only be accessed in the current GIT slice.
The newly implemented backend resolves issues faced in running VirtualBox on distributions supporting UEFI Secure Boot, such as Fedora and RHEL, which reject third-party drivers. Furthermore, KVM support enables VirtualBox operation on Linux systems not compatible with the vboxdrv driver, simultaneous use of VirtualBox alongside other KVM-based virtualization systems, and utilization of advanced hardware virtualization acceleration mechanisms available in KVM but not utilized in VirtualBox, like the APICv extension for interrupt controller virtualization.