Permissions issues with qemu-system-x86_64

[xlash123]

When running the provided run command: sudo docker run --privileged -v /tmp/.X11-unix:/tmp/.X11-unix sickcodes/docker-osx, I get the following errors:

qemu-system-x86_64: warning: dbind: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-r7nn5J3cVN: Connection refused
Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize kvm: Permission denied

I'm not sure what I did wrong. Even running the docker command with sudo doesn't do anything (not that I really expected it to).

The image I pulled is the one from Docker Hub of digest starting with 0eea6e25babb.

I'm running this with Docker CE version 19.03.11, build 42e35e61f3 on Ubuntu 18.04.

[sickcodes]

I've just checked the Docker Hub version and it works for me.

I added some KVM instructions to the readme.

Try the KVM section of the readme and you should be good to go.

[xlash123]

Ah, ok. I didn't know I needed to have that stuff installed as well on the host. I will test it out.

I'm also having the issue. It seems that arch isn't added to the kvm and libvirtd groups and doesn't have permission to use kvm.
EDIT: also /dev/kvm needs to be owned by the kvm group

[roryrjb]

You may have more luck with something like this:

$ docker run --privileged --net host --cap-add=ALL -v /tmp/.X11-unix:/tmp/.X11-unix -v /dev:/dev -v /lib/modules:/lib/modules sickcodes/docker-osx

[xlash123]

I have installed those dependencies and ran the systemctl commands and rebooted, but there's a new error now:

Unable to init server: Could not connect: Connection refused
Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize kvm: Permission denied

I noticed that one of the services that you said to start, virtlogd, doesn't seem to want to start. When running service --status-all, I get (for related services):

 [ + ]  docker
 [ + ]  libvirt-guests
 [ + ]  libvirtd
 [ - ]  virtlogd

The log for that service is:

Jun 04 13:51:04 [redacted] systemd[1]: Started Virtual machine log manager.
Jun 04 13:51:59 [redacted] systemd[1]: Stopping Virtual machine log manager...
Jun 04 13:51:59 [redacted] systemd[1]: Stopped Virtual machine log manager.

Any ideas on where to go from here?

[sickcodes]

Check if your hardware virt is on
egrep -c '(svm|vmx)' /proc/cpuinfo

Try this
sudo usermod -aG docker $USER

Turn on docker daemon
sudo nohup dockerd &

[xlash123]

@sickcodes, I already have virt turned on, docker daemon running, and am part of the docker user group.

The connection refused error went away (not sure how), but the permissions error is still there. Could it be that the user running in the Docker container is trying to use kvm on my machine, but it's not in the user group for KVM, so it fails? I noticed I get the same permissions error when I run kvm on my machine, but since I added myself to the usergroup, the error went away.

[sickcodes]

Try adding all these:
sudo apt install qemu qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virt-manager uml-utilities libguestfs-tools

EDIT: not required, see below for anyone reading.

[luposlip]

I've tried anything in the README and here, and (also) still have the same issue:

docker run --privileged -v /tmp/.X11-unix:/tmp/.X11-unix sickcodes/docker-osx
No protocol specified
Unable to init server: Could not connect: Connection refused
Could not access KVM kernel module: Permission denied
qemu-system-x86_64: failed to initialize kvm: Permission denied

Ubuntu (Pop! OS) 20.04 BTW

@sickcodes

• arch isn't a member of the kvm and libvirtd groups

• /dev/kvm needs to be owned by the kvm group

those two issues cause the permission denied error

[xlash123]

Why are we running qemu on the host? Can't that go inside the Docker container?

[luposlip]

Just tried ghgrp kvm /dev/kvm. Now ls -la /dev/kvm reveals:

crw-rw----+ 1 root kvm 10, 232 Jun  4 20:56 /dev/kvm

Still same error.

[sickcodes]

Mines like this
crw-rw-rw- 1 root kvm 10, 232 Jun 5 03:20 kvm

Try this:

sudo ghgrp kvm /dev/kvm
sudo chmod 666 /dev/kvm

[Write]

You may have more luck with something like this:

$ docker run --privileged --net host --cap-add=ALL -v /tmp/.X11-unix:/tmp/.X11-unix -v /dev:/dev -v /lib/modules:/lib/modules sickcodes/docker-osx

Thanks, it worked for me. Ubuntu 20.04
I still had to sudo and get a few 'errors' but at least QEMU launched and macOS is loading

sudo docker run --privileged --net host --cap-add=ALL -v /tmp/.X11-unix:/tmp/.X11-unix -v /dev:/dev -v /lib/modules:/lib/modules sickcodes/docker-osx
QEMU 5.0.0 monitor - type 'help' for more information
(qemu) ALSA lib pcm_dmix.c:1089:(snd_pcm_dmix_open) unable to open slave
alsa: Could not initialize DAC
alsa: Failed to open `default':
alsa: Reason: No such file or directory
ALSA lib pcm_dmix.c:1089:(snd_pcm_dmix_open) unable to open slave
alsa: Could not initialize DAC
alsa: Failed to open `default':
alsa: Reason: No such file or directory
audio: Failed to create voice `dac'
ALSA lib pcm_dsnoop.c:641:(snd_pcm_dsnoop_open) unable to open slave
alsa: Could not initialize ADC
alsa: Failed to open `default':
alsa: Reason: No such file or directory
ALSA lib pcm_dsnoop.c:641:(snd_pcm_dsnoop_open) unable to open slave
alsa: Could not initialize ADC
alsa: Failed to open `default':
alsa: Reason: No such file or directory
audio: Failed to create voice `adc'

[sickcodes]

These steps should set your host up for the QEMU on https://help.ubuntu.com/community/KVM/Installation