Microsoft appears to be interested in integrating Linux even more deeply within the Windows operating system ecosystem. The company has proposed a few patches that could potentially allow Linux Distros even more native functionality than before. These patches essentially aim to allow Linux distributions to run as Root Partition on the Hyper-V virtualization platform.
Microsoft has submitted a series of patches to the Linux kernel developers. The eventual aim appears “to create a complete virtualization stack with Linux and Microsoft Hypervisor.” The patches are tagged as “RFC” (Request For Comments) and are a minimal implementation presented for discussion.
Microsoft Wants Linux To Run As Natively As Windows OS On Hardware With Root Partition Access On Hyper-V?
Microsoft principal software engineer Wei Liu indicated that Microsoft has submitted a series of patches to Linux kernel developers requesting that Linux run as the root partition on the Hyper-V. The Hyper-V platform is a hypervisor software for running Windows and non-Windows instances on hardware.
The key aspect of these patches is that with the eventually patched kernel, Linux will run as the Hyper-V root partition. In the Hyper-V architecture, the root partition has direct access to hardware and creates child partitions for the VMs it hosts. Consider this similar to Xen’s Dom0, claimed Liu. Incidentally, Hyper-V’s architecture is more similar to Xen than it is to KVM or VMware’s ESXi.
Microsoft: These patches aim to make Linux run as root partition on Hyper-V https://t.co/TLmDrAJb88
— ZDNet (@ZDNet) September 16, 2020
The priority of the proposed patches is extending the Hyper-V Top-Level Functional Specification (TLFS), which governs Hyper-V’s visible behavior, to other operating system components. The specification is primarily targeted towards developers who regularly build guest operating systems.
Microsoft’s main concern about the new implementation of Hyper-V is that it wants Linux kernel developers to change the core Linux kernel’s behavior when accessing hardware memory in a way that affects driver access to the GPU and CPU. Needless to mention, such systems and processes are managed by an operating system’s memory manager, and messing around in these regions is tricky, indicated Liu.
Microsoft Azure And Windows 10 To Benefit From Linux Running As Root Partition On Hyper-V?
Currently, the Hyper-V Root Partition can only run Windows OS. However, if Linux gets access to the Root Partition, the OS simply won’t need to run Windows on that hypervisor. Simply put, Microsoft wants to enable “a complete virtualization stack with Linux” for Microsoft in its Azure cloud. It is important to note that users depending on Linux Distros and their instances on Microsoft Azure exceeded those relying on Microsoft’s own Windows OS, last year. In other words, there are more Linux instances running on Microsoft Azure than Windows virtual OS instances.
Even though Hyper-V can host both virtual machines and containers, there are major architectural differences between the two, and containers serve an entirely different purpose from virtual machines..
— Eager Beaver (@eagerbeavertech) September 16, 2020
While the current developments are centered around Microsoft Azure, they should have a positive impact on Windows 10 OS as well. Needless to add, these developments itself build on Microsoft’s extensive efforts to support developers with Windows 10’s Windows Subsystem for Linux (WSL) and WSL 2, which includes Microsoft’s custom Linux kernel.
Incidentally, Microsoft has also ported Intel’s open-source Cloud Hypervisor. The company has been able to boot a Linux guest with Virtio devices. Intel has developed Cloud Hypervisor, an experimental open-source hypervisor implementation, in the Rust programming language. It’s a virtual-machine monitor that runs on top of KVM, the Kernel-based Virtual Machine hypervisor in the Linux kernel. These are designed for cloud workloads.