Generally speaking, Xen-style virtualization is where each VM has their own copy of the kernel and their own memory space. There are new-ish features like trans

Generally speaking, Xen-style virtualization is where each VM has their own copy of the kernel and their own memory space. There are new-ish features like transcendent memory which can blur the lines, but I don't think they are widely deployed. Systems like docker, LXC, and virtuozzo are where you run into the issue you describe.