Gnome Boxes and network bridge on Ubuntu 22.04

Configure Boxes, then install Virtual Machine Manager and connect it to the QEMU/KVM User session.

Open the VM settings in Virtual Machine Manager and change the network options from Usermode networking to Bridge device, and set virbr0 (the virtual network device listed by ifconfig) as device name.

If you start the VM now, you get errors about missing files and permissions.

sudo mkdir /etc/qemu/

sudo nano /etc/qemu/bridge.conf

Put this line of code into the file and save it:

allow virbr0

Then:

sudo chmod u+s /usr/lib/qemu/qemu-bridge-helper

If you still have problems, it could be apparmor. In that case:

ln -s /etc/apparmor.d/usr.sbin.libvirtd /etc/apparmor.d/disable/

apparmor_parser -R /etc/apparmor.d/usr.sbin.libvirtd