Isn't WSL2 just a VM?
14 comments
·November 24, 2025mindcrash
sedatk
Oh, I thought GPU passthrough was enabled on vanilla Windows 11, but I didn't delve into that feature enough. It's still extremely impressive of course. Perhaps I should write another article about graphical features.
DiabloD3
No, PCI-E passthrough is not enabled on non-Server, and you arguably wouldn't do this on a Windows hypervisor. anyways, you'd do it with a Linux+KVM hypervisor for either Linux or Windows guests.
Using GPU passthrough, however, is allowed. WSL2 does this by using the existing Mesa/DRI/DRM open source stack, but instead of a GPU-specific DRM driver, it is one that speaks WDDM (the DRM equivalent in the Windows driver stack), and only requires a GPU-specific ennoblement package (provided by the vendor, and matches the Windows driver it is talking to; AMD, Nvidia, and Intel all ship one inside of WSL2).
toast0
> No, PCI-E passthrough is not enabled on non-Server, and you arguably wouldn't do this on a Windows hypervisor. anyways, you'd do it with a Linux+KVM hypervisor for either Linux or Windows guests.
If it was enabled on Pro, I would use PCI passthrough. I use hyper-v for a Linux dev environment on a windows workstation. My NIC supports virtual functions, so if I could passthrough one to the dev VM, I wouldn't need software bridging and that might be nice. (OTOH, I don't know if my motherboard has reasonable passthrough groups and all the other stuff that makes passthrough never work for me)
sedatk
Thanks!
evanjrowley
https://learn.microsoft.com/en-us/windows-server/virtualizat...
It relies upon SR-IOV and only several server-specific Nvidia GPUs are listed as supported.
Intel's Flex dGPUs and Arc iGPUs have supported SR-IOV for years now, but they aren't listed there. It would be super awesome if they could add it for Intel Arc iGPUs and desktop versions of Windows. It already works with KVM on Linux!
my123
Regular Hyper-V VMs can use it too but it's not well documented.
The keyword to search for: "GPU-P"
https://learn.microsoft.com/en-us/windows-server/virtualizat...
Thaxll
I always found wsl to be a hack and not a true Linux distro, fake pid 1 not really starting or shutting down ect... Even the docker integration is really odd. I know it was fixed with wsl2 but wsl1 had terrible i/o performance.
pak9rabid
Yes, a VM with extremely tight integration with the Windows environment to make things that would otherwise require lots of time to setup a breeze. I use it as my daily driver for dev work (at work, since we're required to use Windows :( ) and to be honest it's quite pleasant most of the time.
andix
Yes, it's "just" a VM.
WSL2 is a bit like Firecracker for Linux. It's a lightweight VM, with a lot of optimizations here and there. For faster startup, lower memory footprint and so on.
PS: which means you need a lot of memory, if you use WSL2 extensively (multiple Docker containers for example). 8-16 GB on top of your usual workloads is a good starting point. Docker on WSL2 is not a lot of fun with less than 20 GB system memory.
nu11ptr
> For faster startup, lower memory footprint and so on
Any idea how they do this? My WSL2 starts insanely fast, like about 1-2 seconds. I've never seen a linux distro natively boot that fast. Assuming they suppress any sort of BIOS startup screen for starters, but what else?
baq
you can access the internal VM disk via
\\wsl$
null
bobse
[dead]
WSL 2 runs on a subset of Hyper-V, and on a hypervisor, so basically yes.
However, there's some interesting things going on in WSL 2 versus a "normal" Hyper-V virtual machine. For example, a Linux distro running on WSL can (and will) use GPU partitioning (aka PCI/GPU passthrough) and a special implementation of DirectX enabling the installed video card to accelerate graphics within X and/or Wayland.
Although this feature can be enabled with a lot of hacking in both the Linux guest and vanilla Hyper-V on the host (the latter through Powershell) it is officially unsupported on Windows 10 and Windows 11, and is only supported on Windows Server.