Can't get Linux VMs to start

[Ron Gage]

Hi all:

This problem has me completely stumped.  I am on a new 4.21 install on 
CentOS Stream 9 for both management and host.  When I boot a Linux ISO, 
I get something similar to this:

The above is an instance on Centos Stream 9.  I have similar misfortune 
with Debian 12.10 and 13.

Has anyone encountered something like this before?  Any hints on tracing 
this down perhaps?

The only thing I have tried so far was to specify 
guest.cpu.mode=host-passthrough in the agent.properties on the KVM host.

Thank you!

Ron Gage