In a virtual machine monitor such as VMware's ESXi Server, how are shadow page tables implemented?

Question

My understanding is that VMMs such as VMware's ESXi Server maintain shadow page tables to map virtual page addresses of guest operating systems directly to machine (hardware) addresses. I've been told that shadow page tables are then used directly by the processor's paging hardware to allow memory accesses in the VM to execute without translation overhead.

I would like to understand a bit more about how the shadow page table mechanism works in a VMM. Is my high level understanding above correct? If so,

• What kind of data structures are used in the implementation of shadow page tables?

• What is the flow of control from the guest operating system to the hardware?

• Short of straight up reading the source code of an open source VMM, what resources can I look into to learn more about hardware virtualization?

Answer 1

over 50 views and nothing?

I spoke to Vidar Holen over IRC on ##linux on freenode.net. He suggested that I take a look at this AMD technical report. It has proven to be a great resource. Anyone else have other suggestions?