MFC r335030:

Add SPDX tags to vmm(4).

Sponsored by: iXsystems Inc.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

As <machine/pmap.h> is included from <vm/pmap.h>, there is no need to
include it explicitly when <vm/pmap.h> is already included.

Reviewed by: alc, kib
Differential Revision: https://reviews.freebsd.org/D5373

Remove "svn:mergeinfo" property that was dragged along when these files were
svn copied in r273375.

Suggested by: ngie, gjb

Merge projects/bhyve_svm into HEAD.

After this change bhyve supports AMD processors with the SVM/AMD-V hardware
extensions.

More details available here:
https://lists.freebsd.org/pipermail/freebsd-virtualization/2014-October/002905.html

Submitted by: Anish Gupta (akgupt3@gmail.com)
Tested by: Benjamin Perrault (ben.perrault@gmail.com)
Tested by: Willem Jan Withagen (wjw@digiware.nl)

style(9) fixes.
Get rid of unused headers.

Bring (almost) up-to-date with HEAD.

- use the new virtual APIC page
- update to current bhyve APIs

Tested by Anish with multiple FreeBSD SMP VMs on a Phenom,
and verified by myself with light FreeBSD VM testing
on a Sempron 3850 APU.

The issues reported with Linux guests are very likely to still
be here, but this sync eliminates the skew between the
project branch and CURRENT, and should help to determine
the causes.

Some follow-on commits will fix minor cosmetic issues.

Submitted by: Anish Gupta (akgupt3@gmail.com)

Enable memory overcommit for AMD processors.

- No emulation of A/D bits is required since AMD-V RVI
supports A/D bits.
- Enable pmap PT_RVI support(w/o PAT) which is required for
memory over-commit support.
- Other minor fixes:
* Make use of VMCB EXITINTINFO field. If a #VMEXIT happens while
delivering an interrupt, EXITINTINFO has all the details that bhyve
needs to inject the same interrupt.
* SVM h/w decode assist code was incomplete - removed for now.
* Some minor code clean-up (more coming).

Submitted by: Anish Gupta (akgupt3@gmail.com)

Handle VM_PROT_NONE in nested page table code.

Submitted by: Anish Gupta (akgupt3@gmail.com)

- SVM nested paging support
- Define data structures to contain the SVM vcpu context
- Define data structures to contain guest and host software context
- Change license in vmcb.h and vmcb.c to remove references to NetApp that
inadvertently sneaked in when the license text was copied from amdv.c.

Submitted by: Anish Gupta (akgupt3@gmail.com)