qemu-bridge-helper undocumented and broken

qemu output:

access denied by acl file
qemu-system-ppc64: bridge helper failed

Option description:

      -netdev bridge,id=id[,br=bridge][,helper=helper]
           Connect a host TAP network interface to a host bridge device.

           Use the network helper helper to configure the TAP interface and attach it to the bridge. The default network
           helper executable is /path/to/qemu-bridge-helper and the default bridge device is br0.

           Examples:

                   #launch a QEMU instance with the default network helper to
                   #connect a TAP device to bridge br0
                   qemu-system-i386 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1



                   #launch a QEMU instance with the default network helper to
                   #connect a TAP device to bridge qemubr0
                   qemu-system-i386 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1


What is the acl file? What is the interface to qemu-bridge-helper?

Also this is what bridge.conf contains:

# Access control file for qemu bridge helper
# Syntax consists of:
#   # comment (ignored)
#   allow all
#   allow <bridge_name>
#   deny all
#   deny <bridge_name>
#   include /path/to/additional/ACL/file
# Users are blacklisted by default and 'deny' takes precedence over 'allow'.
# Including additional ACL files allows file access permissions to be used as
# a component of the policy to allow access or deny access to specific bridges.

How are users specified? Or is the mention of users bogus?


This is an automated cleanup. This bug report has been moved to QEMU's
new bug tracker on gitlab.com and thus gets marked as 'expired' now.
Please continue with the discussion here:

 https://gitlab.com/qemu-project/qemu/-/issues/177