[Guix System] Can't run VM script because of KVM kernel module permission

[Guix System] Can't run VM script because of KVM kernel module permission

[Jérémy Korwin-Zmijowski]

Hey Guixters !

On my laptop running Guix System, I try to execute a VM from the script
generated by "guix system vm". But I issue the following message :

$ /gnu/store/dxrwz82s34zi33n9h9cpn8sqw5pv4qyz-run-vm.sh
Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize kvm: Permission denied

I already add builders to the kvm group as stated in /etc/group :

kvm:x:984:guixbuilder01,guixbuilder02,guixbuilder03,guixbuilder04,guixb
uilder05,guixbuilder06,guixbuilder07,guixbuilder08,guixbuilder09,guixbu
ilder10
guixbuild:x:30000:guixbuilder01,guixbuilder02,guixbuilder03,guixbuilder
04,guixbuilder05,guixbuilder06,guixbuilder07,guixbuilder08,guixbuilder0
9,guixbuilder10

What do I miss ? :/

Cheers,
Jérémy

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[Mathieu Othacehe]

Hello Jérémy,

> $ /gnu/store/dxrwz82s34zi33n9h9cpn8sqw5pv4qyz-run-vm.sh
> Could not access KVM kernel module: Permission denied
> qemu-system-x86_64: failed to initialize kvm: Permission denied

Are you part of the "kvm" group yourself?

Mathieu

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[Jérémy Korwin-Zmijowski]

Le vendredi 02 avril 2021 à 11:36 +0200, Mathieu Othacehe a écrit :
> Are you part of the "kvm" group yourself?
> 
> Mathieu

Hi Mathiue !

I tried to add myself to the group using :

$ sudo usermod -a -G kvm jeko

Then re-executing the vm script returned the same error.

Jérémy

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[Sergiu Ivanov]

Thus quoth  Jérémy Korwin-Zmijowski  on Fri Apr 02 2021 at 11:39 (+0200):
> Le vendredi 02 avril 2021 à 11:36 +0200, Mathieu Othacehe a écrit :
>> Are you part of the "kvm" group yourself?
>> 
>> Mathieu
>
> Hi Mathiue !
>
> I tried to add myself to the group using :
>
> $ sudo usermod -a -G kvm jeko
>
> Then re-executing the vm script returned the same error.

Just in case: did you logout and login afterwards?

Group attributions need that to become effective.

-
Sergiu

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[Jérémy Korwin-Zmijowski]

Le vendredi 02 avril 2021 à 11:43 +0200, Sergiu Ivanov a écrit :
> Just in case: did you logout and login afterwards?
> 
> Group attributions need that to become effective.
> 
> -
> Sergiu

Hi Sergiu!

That's becoming embarrassing... I rebooted instead of logged out and I
might have lost the group attribution doing so.
Now the VM is running.
Sorry for bothering you with this.

Cheers,
Jérémy !

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[Mathieu Othacehe]

> Now the VM is running.
> Sorry for bothering you with this.

No worries, in fact I was thinking yesterday about adding the user by
default to the "kvm" group when running the installer, to prevent this
kind of issues.

Mathieu

Re: [Guix System] Can't run VM script because of KVM kernel module permission

[divoplade]

Le vendredi 02 avril 2021 à 11:39 +0200, Jérémy Korwin-Zmijowski a
écrit :
> I tried to add myself to the group using :
> 
> $ sudo usermod -a -G kvm jeko

Hello, 

Groups need to be specified in the config.scm file.

You need to edit it, and under "(user-account", find or create the
entry "(supplementary-groups" containing a list of strings.

I have something like this:

(user-account
                (name ...)
                (comment ...)
                (group ...)
                (home-directory ...)
                (supplementary-groups
                 '("wheel" "netdev" "audio" "video" ... "libvirt"
"kvm")))

Reconfigure (and possibly reboot) and it will be better :)