Cause:
When a libvirt API is called all its arguments are copied into a so called RPC packet which is then sent to the daemon where the arguments are extracted and the API is called.
However, in case of virNetworkUpdate() there was a bug which swapped two arguments on the client side as the RPC packet was being constructed.
Consequence:
This resulted in daemon having two arguments swapped which ten lead to spurious errors. For instance, when user wanted to add a TXT record to a network the following error was reported:
Operation not supported: can't update 'ip' section of network 'net-1'
Fix:
The fix consists of fixing the order of arguments so that the correct order is preserved.
Result:
Users can now update their networks happily.
More info can be found in the cover letter of original patches:
https://listman.redhat.com/archives/libvir-list/2021-March/msg00052.html
https://listman.redhat.com/archives/libvir-list/2021-March/msg00758.html
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Moderate: virt:rhel and virt-devel:rhel security and bug fix update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2022:0759
Reproduce the bug on libvirt-6.0.0-35.1.module+el8.4.0+11273+64eb94ef.x86_64 # cat split_daemon.sh #!/bin/bash systemctl stop libvirtd.service systemctl stop libvirtd{,-ro,-admin,-tcp,-tls}.socket systemctl start virtqemud for drv in qemu interface network nodedev nwfilter secret storage proxy; do systemctl start virt${drv}d{,-ro,-admin}.socket ; done # ./split_daemon.sh Warning: Stopping libvirtd.service, but it can still be activated by: libvirtd-ro.socket libvirtd.socket libvirtd-admin.socket # virsh -c qemu:///system net-update default add dns-txt '<txt name="example" value="example value"/>' error: Failed to update network default error: Operation not supported: can't update 'ip' section of network 'default' Update libvirt to libvirt-6.0.0-35.2.module+el8.4.0+14226+d39fa4ab.x86_64, and test again, the result is as expected. # virsh -c qemu:///system net-update default add dns-txt '<txt name="example" value="example value"/>' Updated network default live state # virsh -c qemu:///system net-dumpxml default <network> <name>default</name> <uuid>03a68dea-3acc-4dea-831e-15de6ac3329d</uuid> <forward mode='nat'> <nat> <port start='1024' end='65535'/> </nat> </forward> <bridge name='virbr0' stp='on' delay='0'/> <mac address='52:54:00:8a:bf:51'/> <dns> <txt name='example' value='example value'/> </dns> <ip address='192.168.122.1' netmask='255.255.255.0'> <dhcp> <range start='192.168.122.2' end='192.168.122.254'/> </dhcp> </ip> </network> # virsh -c qemu:///system net-update default delete dns-txt '<txt name="example" value="example value"/>' Updated network default live state # virsh -c network:///system net-update default add ip-dhcp-host '<host mac="7e:75:1a:57:b9:55" name="libvirt" ip="192.168.122.100"></host>' Updated network default live state # virsh -c qemu:///system net-dumpxml default <network> <name>default</name> <uuid>03a68dea-3acc-4dea-831e-15de6ac3329d</uuid> <forward mode='nat'> <nat> <port start='1024' end='65535'/> </nat> </forward> <bridge name='virbr0' stp='on' delay='0'/> <mac address='52:54:00:8a:bf:51'/> <ip address='192.168.122.1' netmask='255.255.255.0'> <dhcp> <range start='192.168.122.2' end='192.168.122.254'/> <host mac='7e:75:1a:57:b9:55' name='libvirt' ip='192.168.122.100'/> </dhcp> </ip> </network>