Looking Glass Released For KVM Frame Relay, High Performance Windows VM Gaming

[polarathene]

All modern laptops are like this. From like 2013 onwards or so the physical screen (both internal and external ports) are connected to the iGPU, while the "dedicated" GPU is a headless 3D accelerator.

My laptop is from 2014(860m gpu), unable to do the passthrough properly. I am considering that older laptop. If I remember correctly, nvidia made some big change to way their mobile GPU are configured for laptops with Pascal range? Was a long time ago, article might have been on Phoronix. I believe most users that had success with nvidia gpu in laptops were quadro cards(not because of the KVM blocking non-quadro, but presumably wired differently than consumer cards when used in laptops).

It would defy most of the point. If you give Windows the host seat then you can just use VMWare or Virtualbox for Linux.

Not really. You can run linux as lightweight hypervisor. It has some really nice features vs alternatives(cost being one of them). VMWare afaik doesn't support passthrough of hardware(it can do things like USB devices, but not the controller or other PCI devices), that requires ESXi iirc. Virtualbox has similar issues, they're type 2 hypervisor. You can run Linux as a main OS via VM and also a Windows VM, alternating which one you want to run if you only have a single GPU. There is still advantages to that vs dual boot.

For work, we have a machine that can provide several systems during day for staff to do digital content creation, then at night bring those down and assign all GPU and other resources to a single VM instance to do heavy processing. Also has the benefit of being able to spin up a VM with whatever resources for temporary contract workers too with close to native performance

Nothing wrong with have light host provide the hypervisor and just deal with that while actual OS used by users is all VMs. Host can run as headless, several options out there that provide web UI to manage the VMs, can then have dedicated tablet or just use a browser to access the UI and start/stop VMs(or schedule them without UI if you have usage pattern like my work).

[Danniello]

Not really. You can run linux as lightweight hypervisor. It has some really nice features vs alternatives(cost being one of them). VMWare afaik doesn't support passthrough of hardware(it can do things like USB devices, but not the controller or other PCI devices), that requires ESXi iirc. Virtualbox has similar issues, they're type 2 hypervisor. You can run Linux as a main OS via VM and also a Windows VM, alternating which one you want to run if you only have a single GPU. There is still advantages to that vs dual boot.

Linux lightweight hypervisor (internal GPU or no GPU) with:
* VM1 Linux "main" machine (GPU passthrough)
* VM2 Windows app/gaming machine (GPU passthrough)

So when I want play game I need... stop VM1 (for release GPU) then start VM2... I doesn't make sense... It is almost exactly the same like dual booting (except that hypervisor gives snapshots management, etc.).

I will stay with my current "workaround".
Linux "main" machine (internal GPU) with:
* VM Windows app/gaming machine (GPU passthrough)
This solution is also bad because of very bad internal GPU. Normally I'm using Linux "main" machine with dedicated nVidia card, because my internal Intel GPU is soo bad (no DisplayPort, only HDMI with max. 2560x1440@60Hz... My monitor is 2560x1440@144Hz capable so Intel 60Hz is unacceptable

[tuomi]

So, you are installing Linux, and then installing Windows in a VM, but you want to get native Windows performance and to take over your main monitor with Windows to play a video game?

Many of us use or would like to use our linux-desktops for 24/7 stuff for the home-network etc. and not disrupt this to dual-boot into windows when having time for a gaming session. Not only does this solution compete with the likes of Wine, VirtualBox and VmWare I'd say it blows them out of the water as the support for stuff like OpenGL, DirectX and Vulkan is native.

[polarathene]

So when I want play game I need... stop VM1 (for release GPU) then start VM2... I doesn't make sense... It is almost exactly the same like dual booting (except that hypervisor gives snapshots management, etc.).

This solution is also bad because of very bad internal GPU.

It is up to you. Before when updates were always forced on Windows 10, it was problem for me, usually I don't need internet on the Windows machine, just have it disabled, but could use internet still and browse on host Linux. With VMs I can have internal NAS with fast shared storage(until 10Gigabit+ become more common, thunderbolt probably). I also like to run additional linux VMs for different project work or testing things, but still have native hardware access/performance.

Snapshots don't quite work with GPU passthrough, only if you do offline snapshot of disk image(if not passing through disk directly). Usually I just hibernate to release the GPU and keep my Windows state. I can keep running linux as host like you mention, then for gaming on linux, I can just run linux VM with GPU. I prefer this over dual boot, no worries of Windows update mess with bootloader. I don't see much point in have headless host if only running one OS at a time if you have iGPU available. If don't use Windows for much, might be better to have as VM over dual boot, you can do things like using Intel iGPU transfer your VM from workstation to laptop and continue working on that device with same state(obviously not so useful if you use Windows just for gaming).

You can try use bumblebee for your situation. Host can use iGPU, then do bumblebee when it need to use the dGPU, when not using on host, VM can attach the GPU and use it instead. Slight perf overhead with bumblebee but might be worthwhile to you

[starshipeleven]

I am considering that older laptop.

I only remember that older laptops had hardware switches on phyisical outputs, and you could control this hardware switching with "VGA switcheroo" tool from linux. Maybe you can try searching for laptops supporting that. I'm afraid I can't help much more than this.

Not really. You can run linux as lightweight hypervisor.

Yes I know of KVM. My point is that the only OS that really needs GPU passthrough in what I think is the "average setup" is Windows (otherwise you could just put it in a Virtualbox/VMWare VM and close the case), while Linux will do fine in WMWare or Virtualbox.

Nothing wrong with have light host provide the hypervisor and just deal with that while actual OS used by users is all VMs. Host can run as headless, several options out there that provide web UI to manage the VMs, can then have dedicated tablet or just use a browser to access the UI and start/stop VMs(or schedule them without UI if you have usage pattern like my work).

Again I was assuming single-PC usage, it's kind of awkward to have to use my smartphone to control my PC/Laptop's hypervisor to start up my "main OS" (a VM) that has a GUI.

The discussion I was in was about people making KVM VMs with passthrough for gaming on a single PC with a single screen.

[danboid]

Hopefully Intel will add support for Looking Glass to GVT-G to make it actually usable.

[polarathene]

Hopefully Intel will add support for Looking Glass to GVT-G to make it actually usable.

The demos from few years ago showed it doing something like VT switching on single display from linux to windows iirc. Not sure of specifics, but they had something working back then, why it might not be present now I don't know.