如何查找我的操作系统是在虚拟化还是非虚拟化环境中运行？

I have access to a machine to which I can ssh. How to determine if my OS is running in fully-virtualized (where VMM does binary translation), para-virtualized or non-virtualized environment? I have some idea of how to go about it (some operations like accessing a memory page/disk will take longer time in a virtualized environment) but don't know how to proceed. I have access to a machine to which I can ssh.