Hello Michael,
Just to clarify, how may physical CPU cores are on the host system? You mention that you have two cores, hyperthreaded, and it seems as though you have four vCPUs allocated to the guest machince. If you only have two physical CPU cores, this will probably cause excessively high CPU Ready times, which will cause high CPU usage on the guest and low CPU usage on the host (because the host is waiting for four CPUs to available before scheduling them to the guest, which would be hard for it to do with only two cores + hyperthreading).
If you have only two physical CPU cores on the host, I recommend not assigning more than one, two at the most, to the guest, otherwise you'll going to run into CPU scheduling issues (high CPU Ready times). Have you tried running the guest machine with a single vCPU assigned?
Greg