Unfortunately there are too many abbreviations in this industry, (insert personal rant about understandability V TLA fluency). KVM can mean
Kernel based Virtual Machine - which allows you create several virtual machines within a single instance of the OS.
Keyboard, Video, Mouse - A physical device for unifying access to several hosts within a single switch.
i suspect your mis-understanding of the power of KVM may result from a cross-pollination of these two meanings.
What you require is to cluster the physical hosts into a single instance... a non-definitive list of clustering solutions is available at
Comparison of cluster software - Wikipedia, the free encyclopedia