kvm permission denied on Android Studio emulator

Question

When I try to run an AVD, I get this erros:

/dev/kvm device permission denied

Yeah, I know, I don't have the permission to access /dev/kvm, I know that I can "solve" it by changing the /dev/kvm permission to my user, and set my user to kvm group, it is working but when I restart my user session, the /dev/kvm permission return to root user and root group, and I need to set the permission to my group again and again...

How to set this permission and prevent that when I reboot my computer my permission are not changed anymore?

SO: Ubuntu 18.04.01

Mokpo

Is your user in kvm group? – Devastating

yes, my user are on the kvm group and I already treid the 777 permission too... – Mokpo

Did you install all required dependencies as mentioned in official guide? developer.android.com/studio/run/emulator-acceleration#vm-linux and help.ubuntu.com/community/KVM/Installation – Devastating

yes, the problems is: The folder permission and user/group are changin to root every time I logout/turn off my computer – Mokpo

Can you try this and tell if it works for you: sudo setfacl -m u:$USER:rwx /dev/kvm – Devastating

That worked @AndreiVinogradov :) ... What does command do exactly? – Grover

I posted this comment as answer with a little explanation. Please, accept it. ) – Devastating

Answer 1

This command should help you:

sudo setfacl -m u:$USER:rwx /dev/kvm

Using it you will grant to current user rwx permissions to /dev/kvm. Or just replace $USER to any user you need.

As mentioned in setfacl manpages "This utility sets Access Control Lists (ACLs) of files and directories." It's a little bit different from chmod and chown. Using it you can grant required permissions to specific user. It's a bit more powerful tool and much more fine-grained. If you want to dive deeper, read about Access Control Lists. For example, in ubuntu docs: https://help.ubuntu.com/community/FilePermissionsACLs

Devastating

it not worked, if I restart my computer, the permission return. – Mokpo

Is package qemu-kvm installed? – Devastating

I see two options here. 1) Completely remove qemu-kvm using command "sudo apt autoremove qemu-kvm --purge" and then reinstall it. 2) Add command to set permissions on /dev/kvm to any boot-time script like .bashrc. – Devastating

ok, it worked if I put on .bashrc, I think it have other better things to fix that... But ok... – Mokpo

Answer 2

Had same problem, it worked when you restart the program.

sudo chmod 777 -R /dev/kvm

Tehuantepec

Answer 3

Permissions for kernel virtual machine can be updated with the command sudo chmod 777 -R /dev/kvm in ubuntu system.

Governess

Answer 4

Update system BIOS Setting Assus

1. Power on the system and press[delete] key to enter BIOS [EZ Mode]
2. Press [F7] key to enter BIOS [Advance Mode] as below picture： (If press [delete] key to enter [Advanced Mode] directly and then no need to press [F7] key any more)
3. Select [Advanced] page and click [CPU Configuration] item
4. Select [Intel(VMX) Virtualization Technology] item and set to [Enabled]
5. Press [F10] key and click [OK] ,the system will auto reboot

Vogt

Answer 5

The right permissions are:

sudo chmod 666 /dev/kvm

Tracitracie

Please make sure to explain your solution and how it is different from the previous answers. Also if you're stating something (as a fact) you should usually include at least one source. – Cracknel