Unable to attach winaps using Docker

[quadroli]

I get the error:

Error response from daemon: error gathering device information while adding custom device "/dev/kvm": no such file or directory

Dispite the file existing which is confirmed by the output from kvm-ok which is

INFO: /dev/kvm exists
KVM acceleration can be used

I have added my user to the kvm group
I am on Ubuntu 24.04
And I am using the default compose.yaml

[cjk268]

I'm getting the same error (Linux Mint 22.1)

$ ls -l /dev/kvm
crw-rw----+ 1 root kvm 10, 232 Aug 27 20:01 /dev/kvm

Tried setting the KVM: "N" on the compose environment from this dockur issue which did not work.

Setting privileged: true in the compose file did work and started downloading Windows 11.

I'm assuming it's a user permissions issue with Docker? Does anyone know if this edit to the compose file is a viable solution or is it harmful/ can I go about it a better way?

[cjk268]

Just to note, setting privileged: true doesn't get you a whole lot further.

[cjk268]

For future reference to others, solution on here worked for me

If you were trying to run the container via Docker Desktop and received this error, you can try to use Docker Engine directly. Docker desktop uses a virtual context desktop-linux which does not have enough permission to /dev/kvm, see here: Install Docker Desktop on Linux.

Docker Desktop for Linux and Docker Engine can be installed side-by-side on the same machine (but do not run them simultaneously). So what you need to do is:

1. Stop docker desktop by clicking `Quit Docker Desktop` or executing:

systemctl --user stop docker-desktop

2. Install docker engine. Instructions can be found here: [Install Docker Engine](https://docs.docker.com/engine/install/)

3. Run docker with `sudo`. You won't need parameter `--privileged`.

and

If you are using Docker Desktop for Linux and encounters an error indicating the /dev/kvm is missing, permission is not adequate or kvm acceleration is not available while kvm-ok check receives no error, try to use docker daemon directly without Docker Desktop.

The key reason for the fact that docker daemon (from Docker Desktop) fails to find /dev/kvm is that the docker daemon runs in a virtual machine created by Docker Desktop, not on the host (like docker engine does), so it cannot access the low-level hardwares like /dev/kvm and it will fail at the device mounting step, see here: Why does Docker Desktop for Linux run a VM?. Even with --privileged, the docker daemon in the VM can start with no error and mount /dev/kvm, but this is a low-level hardware, and Docker Desktop only builds mappings for high-level hardwares, so the container eventually fails at the step where it trys to communicate with the device.