Re: non-root bridge set-up on Fedora 39 aarch64

On Mon, Feb 26, 2024 at 03:12:51PM -0500, Chuck Lever wrote: > > > > > > > > Hello- > > > > > > > > > > > > > > > > I'm somewhat new to the libvirt world, and I've encountered a problem > > > > > > > > that needs better troubleshooting skills than I have. I've searched > > > > > > > > Google/Ecosia and stackoverflow without finding a solution. > > > > > > > > > > > > > > > > I set up libvirt on an x86_64 system without a problem, but on my > > > > > > > > new aarch64 / Fedora 39 system, virsh doesn't seem to want to start > > > > > > > > virbr0 when run from my own user account: > > > > > > > > > > > > > > > > cel@boudin:~/kdevops$ virsh net-start default > > > > > > > > error: Failed to start network default > > > > > > > > error: error creating bridge interface virbr0: Operation not permitted > > > > > > > > > > > > > > > > > > > > > If you run virsh as a normal user, it will auto-create an unprivileged > > > > > > > ("session mode") libvirt instance, and connect to that rather than the > > > > > > > single privileged (ie. run as root) libvirt instance that is managed by > > > > > > > systemd. Because this libvirt is running as a normal user with no elevated > > > > > > > privileges, it is unable to create a virtual network. > > > > > > > > > > > > > > > > > > > > > What you probably wanted to do was to connect to the system-wide privileged > > > > > > > libvirt, you can do this by either running virsh as root (or with sudo), or > > > > > > > by using > > > > > > > > > > > > > > > > > > > > >   # virsh -c qemu:///system > > > > > > > > > > > > > > > > > > > > > rather than straight "virsh". Whichever method you choose, you'll want to do > > > > > > > that for all of your virsh commands, both for creating/managing networks and > > > > > > > guests. > > > > > > > > > > > > These are wrapped up in scripts and ansible playbooks, so I'll have > > > > > > to dig through that to figure out which connection is being used. > > > > > > Strange that this all works on my x86_64 system, but not on aarch64. > > I found the answer; posting here for the archive. > > There was a bug in the Ansible playbook responsible for setting up > libvirt to "run as a regular user". It was enabling libvirtd, but > was failing to enable virtnetworkd. On Fedora systems, both of > these steps are necessary. > > Once that was corrected, virtual networking works without error. Glad to hear you managed to figure it out. As suspected, it wasn't an aarch64-related issue after all :) Note that you shouldn't enable both the monolithic daemon (libvirtd) and the modular daemons (virtnetworkd, virtqemud) at the same time. If your version of libvirt is recent enough (>= 9.9.0) the situation should be handled cleanly, but in general it's not a supported configuration.

Moreover, Fedora has defaulted to modular daemons for a long time now, so really you shouldn't need to do anything special to ensure that they are enabled. Just install the package, then either start the various services/sockets manually or simply reboot. That should do the trick.