Virtual machines VNC bug

[Kuba1842]

Explain what happens

Hi,

i am using Cockpit mostly for control virtual servers and when i am edit virtual server RAM or Disk boot or something like that on Cockpit, VNC display showing right on the page stop working and Cockpit event log showing: "argument unsupported: QEMU guest agent is not configured".. and when i am look at libvirt machine files, after editing RAM or Disk boot or something, machine xml configuration changed a lot options between machines, where VNC display working.

e.g this on edited machine missing: <channel type='unix'> <target type='virtio' name='org.qemu.guest_agent.0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> (and when i added it manually, VNC display on Cockpit still doesnt works..)

sorry for my bad english, i hope you understand what i mean :-)

Version of Cockpit

277 machines (cockpit 279)

Where is the problem in Cockpit?

Applications

Server operating system

Debian

Server operating system version

Debian 11

What browsers are you using?

Chrome

System log

libvirtd[1025]: argument unsupported: QEMU guest agent is not configured

[KKoukiou]

@Kuba1842 thanks for the bug report and sorry for taking long time to reply. This got lost over the christmas holidays. Do you have some custom VNC conifguration in your VMs XML?

Can you maybe post the whole reproducer workflow? Like how did you create the VMs, then what exact option did you edit from the UI, was the VM running or shut off and then exactly what was the diff the XML before and after the option change. Thanks in advance for the reproducer details.

[Kuba1842]

Hi, thanks for your answer.

I do everything directly through the Cockpit. I'll give you a specific case:

• I create a new virtual machine via Cockpit, e.g. debian - during installation VNC works directly via Cockpit without any problems..
• Then I just turned off the server via cockpit.. turned it on again and VNC didn't load anymore (which is even different than when I created the issue, VNC didn't work for me only after modifying RAM when the virtual machine was turned off)

It show just connecting:

and Logs shows:

But I do everything through Cockpit, I don't interfere with virtual machines with ssh commands or directly into the XML file. Just as I wrote, I noticed that after modifying the RAM of the virtual machine, it changed quite a few settings in the XML and then as if VNC was not configured at all.