Microsoft’s latest patch for the Linux kernel is designed to extend kernel support by allowing running on nested Microsoft (MSHV) hypervisors, i.e., running multiple instances of Linux and even running additional operating systems within a running virtual machine system.
Jinank Jain of Microsoft’s Linux team issued a set of patches on Wednesday to add support for running Linux on nested Microsoft hypervisors. There are specific Hypercalls that need to be redirected to the L0 hypervisor instead of the L1 hypervisor, and this patch series is making changes to them.
With just over 100 lines of new code, the handling of nested Hypercalls in the Microsoft/MSHV support code has been implemented to allow the creation of nested hypervisor support, i.e. Hyper-V running Hyper-V again in a Hyper-V virtual machine.
This work is currently resting on this patch series. If the code review goes well, this nested Microsoft Hypervisor support may gain traction in the Linux v6.2 kernel cycle.