Microsoft Continues Working On Hyper-V Dom0 Support For Linux

[phoronix]

Phoronix: Microsoft Continues Working On Hyper-V Dom0 Support For Linux

Microsoft Linux engineers have continued preparing the Linux kernel to support Hyper-V Dom0 for Linux to run as the root partition...

https://www.phoronix.com/news/Microsoft-Hyper-V-Dom0-Linux

[junkbustr]

I'm a bit confused here.

AFAIK, in Windows, Hyper-V is a Type1 hypervisor similar to Xen. Windows and WSL2 run as VM's on top of Hyper-V.

Does this mean that the Linux kernel could/would replace Hyper-V as the hypervisor under Windows?

Or is this another page from Microsoft's long history of EEE (Embrace, Extend, Extinguish)?

[mobadboy]

I'm a bit confused here.

AFAIK, in Windows, Hyper-V is a Type1 hypervisor similar to Xen. Windows and WSL2 run as VM's on top of Hyper-V.

Does this mean that the Linux kernel could/would replace Hyper-V as the hypervisor under Windows?

Or is this another page from Microsoft's long history of EEE (Embrace, Extend, Extinguish)?

hyper-v today
dom0: windows
domU: linux, freebsd, another windows vm

hyper-v after this:
dom0: windows OR linux
domU: linux, freebsd, another windows vm

it changes nothing about hyper-v on windows, but now you can replace xen with hyper-v on linux in theory

looking forward to a highly performant and capable competitor to xen which is basically standard in security-critical situations, unless you're a hyperscaler and somehow have cloud-hypervisor (KVM) running at scale

avoid qemu at all costs in security-critical situations, e.g. malware research

[Sonadow]

hyper-v today
dom0: windows
domU: linux, freebsd, another windows vm

hyper-v after this:
dom0: windows OR linux
domU: linux, freebsd, another windows vm

it changes nothing about hyper-v on windows, but now you can replace xen with hyper-v on linux in theory

looking forward to a highly performant and capable competitor to xen which is basically standard in security-critical situations, unless you're a hyperscaler and somehow have cloud-hypervisor (KVM) running at scale

avoid qemu at all costs in security-critical situations, e.g. malware research

Interesting. Hyper-V on Linux. Looking forward to it. And it will be extremely desirable if it Microsoft also ports over the Hyper-V management GUI for users who prefer to fully manage Hyper-V, vNICs and vswitches via an easy point-and-click GUI. Even better if this management GUI can be accessed over a browser.

Next step: making the Linux kernel Hyper-V aware when running in domU so that paravirtualization is possible. Useful on consumer-grade hardware where the UEFI does not allowing enable AMD SVM or Intel VTx

[Quackdoc]

A lot of Hyper-v tooling is actually really nice to use, I wonder if they will make some of it available on linux

[Alex Doe]

Interesting. Hyper-V on Linux. Looking forward to it. And it will be extremely desirable if it Microsoft also ports over the Hyper-V management GUI for users who prefer to fully manage Hyper-V, vNICs and vswitches via an easy point-and-click GUI. Even better if this management GUI can be accessed over a browser.

Why would they do that? You can just buy Win Pro and configure all the things remotely. I did that many years ago with Hyper-V server (it had no GUI at all) and Samba based domain controller as well.

[oiaohm]

Next step: making the Linux kernel Hyper-V aware when running in domU so that paravirtualization is possible. Useful on consumer-grade hardware where the UEFI does not allowing enable AMD SVM or Intel VTx

https://servermall.com/blog/hyper-v-server-hardware-requirements/

All versions of hyper-v required AMD SVM or Intel VT to function. This is the hyper-v hypervisor itself limitation.

https://www.youtube.com/watch?v=YrEq-o16yiw This video is a little flicker sorry to say bad recording. Pagetable-based Virtual Machine (PVM) is being worked on for Linux kernel. Xen is able todo Pagetable based virtualization. Yes existing KVM has the same Hyper-v limitation.

https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/virtualization_deployment_and_administration_guide/chap-kvm_para_virtualized_virtio_drivers

paravirtualization support in does not change the hypervisor design.

[oiaohm]

Why would they do that? You can just buy Win Pro and configure all the things remotely. I did that many years ago with Hyper-V server (it had no GUI at all) and Samba based domain controller as well.

https://www.papercut.com/kb/Main/WindowsConnectionLimit/

To be legal should have been less than 20 device network due to Windows Pro limit Alex Doe and over 20 connections odd things can happen from time to time due to running out of connections allowed. If it was not do not say. Linux kernel advantage here is no connection limit or microsoft cal to deal with in the host OS.

This is the thing I wonder if Microsoft own CAL licensing is causing them internal troubles.

[sharpjs]

I'm pretty excited for this. Windows runs well on Hyper-V, so I hope that this will enable a better Windows experience for Linux users (or potential users) who, like myself, need to spend significant time in Windows for work. AIUI, Hyper-V has some fractional GPU paravirtualization that WSLg can use. If that were to be available in the reverse direction, that would be a win for those of us who don't want the hassle of a second GPU and VFIO.