CFT: nested page table integration with amd64/pmap

[Neel Natu]

Hi,

The projects/bhyve_npt_pmap branch modifies the amd64/pmap to be able to
deal with Intel EPT mappings in addition to the regular x86 page tables.

This provides bhyve with the following features:

1. Memory overcommit
Guest memory is now pageable and therefore virtual machines can allocate
more memory than is physically available on the host.

2. Superpage mappings for guest memory
Guest physical address mappings can be transparently promoted to superpages
depending on memory locality and access patterns.

3. PCI passthru
PCI passthru is not a new feature but we want to highlight that there
haven't been any regressions in its functionality.

The code is available here:
http://svnweb.freebsd.org/base/projects/bhyve_npt_pmap

Please give it a spin and let us know how it goes.

best
Neel