Virtual Machine Manager says hypervisor is not running with the libvirtd-desktop sysext enabled

[arturasb]

Hi.

My setup:

1. Fedora Silverblue 42 fresh install on Framework 13" AMD (1st gen).
2. systexts-manager and libvirtd-desktop sysexts are installed as per relevant instructions.
3. virt-manager is installed as a flatpak from Flathub to user space, user is systemd-homed managed.

The issue is that with libvirt and relevant services enabled, the Virtual Machine Manager is complaining that default hypervisor is not detected. Checked and with non-systemd-homed managed user - same issue.

I cannot find relevant anomalies in the logs. Any thoughts what could be missing or wrong? What else to check ?

Regards
ArturasB.

[travier]

That's weird. Can you copy/paste the exact message here? Thanks

[arturasb]

Sure.

systemctl status libvirtd.service:

● libvirtd.service - libvirt legacy monolithic daemon
     Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; preset: disabled)
    Drop-In: /usr/lib/systemd/system/service.d
             └─10-timeout-abort.conf
     Active: active (running) since Wed 2025-10-29 22:32:46 EET; 2s ago
 Invocation: 510324e64db74acab5e0997aeda55e92
TriggeredBy: ○ libvirtd-admin.socket
             ○ libvirtd.socket
             ○ libvirtd-ro.socket
       Docs: man:libvirtd(8)
             https://libvirt.org/
   Main PID: 4419 (libvirtd)
      Tasks: 21 (limit: 32768)
     Memory: 20.3M (peak: 22.6M)
        CPU: 355ms
     CGroup: /system.slice/libvirtd.service
             └─4419 /usr/bin/libvirtd --timeout 120

Oct 29 22:32:46 fedora systemd[1]: Starting libvirtd.service - libvirt legacy monolithic daemon...

Oct 29 22:32:46 fedora systemd[1]: Started libvirtd.service - libvirt legacy monolithic daemon.

virt-manager:

[arturasb]

P.S.: if I try creating new connection I get the following error:

# cat /etc/polkit-1/rules.d/50-libvirt.rules 
polkit.addRule(function(action, subject) {
    if (action.id == "org.libvirt.unix.manage" &&
        subject.isInGroup("wheel")) {
            return polkit.Result.YES;
    }
});

I can create user session, but I get this as soon as I try adding a VM:

[arturasb]

I dug a bit more looking for clues what could be wrong:

• No libvirt group
• No PolKit policies/rules installed
• Probably something more is missing

I wonder if the sysext is supposed to provide all those bits, or a user must create it manually.

[travier]

Have you followed the instructions from https://fedora-sysexts.github.io/fedora/libvirtd-desktop/#how-to-use ?

[arturasb]

Yes, of course.

[C-L-Istre]

I dug a bit more looking for clues what could be wrong:

• No libvirt group
• No PolKit policies/rules installed
• Probably something more is missing

I wonder if the sysext is supposed to provide all those bits, or a user must create it manually.

I don't want to hijack this but I might be having a similar issue. I did a fresh install of kinoite 43 this morning and after installing the sysext, the libvirt group was there (I skipped the 'Setup auth via polkit' step), but I did have the same issue initially. Unfortunately, I don't remember what fixed it (it might have just been restarting libvirt a few more times) but I was able to connect to QEMU as expected shortly after.

• Probably something more is missing

Speaking to this, you might be right, although it is probably more likely that I am missing something obvious because I can not get virtual networks working in either virt-manager or directly with virsh. When trying to create one in virt-manager I just get a permission error.

Error starting network 'default': couldn't write dnsmasq config file '/var/lib/libvirt/dnsmasq/default.conf': Permission denied

I was able to manually create a default network with virsh which does now show up in virt-manager but it will not start, giving the same error message above. No amount of permission/ownership change was able to get me past this issue which I suspected (I assume this is just SELinux doing its job?).

Is this expected behavior or should a default network have been created during the sysext installation? I am willing to do another fresh install to help identify any potential issues but don't want to do so preemptively if I am missing something obvious and it is not related to the issue @arturasb is having.

[travier]

Ah yes, I sometimes have to close virt-manager and restart it if I launched it before the libvirt daemons are started.

[C-L-Istre]

That is probably what fixed it for me. I am planning on doing a fresh install of f43 in a few minutes so I will see if I can reproduce either challenge. If I still have the networking problem should I create a separate issue, or did I just miss some documentation?

[travier]

I don't remember having issues with networking but I was starting from a previously layered installation. Likely an other issue.

[C-L-Istre]

I was able to reproduce the error, however, it was solved with a reboot so it may be a non-issue that could be avoided by removing some ambiguity in the install instructions:

Reboot your system or refresh the merged sysexts:

sudo systemctl restart systemd-sysext.service
systemd-sysext status

Note that this will merge all installed sysexts unconditionally.

It seems that a reboot is not optional.

Steps to reproduce and resolve on fresh install (no updates were performed) of Fedora-Kinoite-ostree-x86_64-43-1.6:

1. Completed 'First time setup' followed by 'Installation' under Usage instructions
2. Created the qemu user, copied the default configs and restarted libvirtd as shown in How to use (I skipped 'Setup auth via polkit')
3. Installed the virt-manager flatpak through 'Discover'
4. Launched virt-manager and received the same error as @arturasb when trying to connect to the session
5. Tested the user session, it connected fine but was inoperable (permission errors when trying to create a network or VM)
6. Stopped virt-manager and re-ran $ sudo systemctl restart virtqemud.socket virtnetworkd.socket virtstoraged.socket, no change
7. Rebooted system
8. Started virt-manager, was prompted for a password, both sessions connected after authentication

Unfortunately, the other issue is worse than I thought. Neither session seems to have permission to even create VMs, let alone a virtual network.

[arturasb]

Hi.

I decided to upgrade to Fedora Silverblue 43 and try again with with libvirtd-desktop sysext.
The OS upgraded successfully. Next, sudo systexts-manager update:

[ERROR sysexts_manager_lib::manager] Failed to update sysext: libvirtd-desktop: No such file or directory (os error 2)

Tried updating by following update command from here https://fedora-sysexts.github.io/fedora/libvirtd-desktop/

sudo /usr/lib/systemd/systemd-sysupdate update --component libvirtd-desktop

and got the following error:

No transfer definitions for component 'libvirtd-desktop' found.

How do I update systexts-manager itself and then the libvirtd-desktop to the version 43 ?

[travier]

I don't have a build of the sysexts-manager for F43 yet. I'll have to do that first: travier/sysexts-manager#48