Hi all,
Not sure if this is the right place to ask this but I have noticed on a couple of my servers running ubuntu server VM’s on top of a ubuntu server host with KVM that after a little while the console freezes. SSH still works, the shutdown button still works but using either virt-manager or cockpit-machines the console in the VM is frozen.
Any help would be greatly appreciated 
Warm regards,
If you have working SSH, you can run “journalctl” in follow mode to correlate the console freeze with error messages to begin troubleshooting:
journalctl -f -o short-iso
For example, years ago I had a similar situation with a QEMU-KVM host. Everything worked fine on the host, all the guests continued to run without issue, SSH was working, but the host screen locked/froze. In my case, it turned out to be my stubborn use of the Nouveau video driver, and I would see something like the following:
kernel: [14690.709515] nouveau 0000:02:00.0: gr: TRAP ch 4 [007f5a3000 Xorg[1435]]
I fixed it by switching from the somewhat open source Nouveau driver to the proprietary Nvidia driver.
Hope that helps!