First cut at porting the kernel portions of 221828 and 221905 from the
BHyVe reference branch to HEAD.
Enable handling of 1GB pages in the direct map since HEAD supports those.

Submitted by:	neel
First cut to port bhyve, vmmctl, and libvmmapi to HEAD.
Remove misleading macro definition (-DOLD_BINUTILS) from CFLAGS.

At this point we require binutils from ports that understands how to
assemble the VT-x instructions.

Discussed with: grehan@
Changes to allow the GENERIC+bhye kernel built from this branch to
run as a 1/2 CPU guest on an 8.1 bhyve host.

bhyve/inout.c
      inout.h
      fbsdrun.c
 - Rather than exiting on accesses to unhandled i/o ports, emulate
   hardware by returning -1 on reads and ignoring writes to unhandled
   ports. Support the previous mode by allowing a 'strict' parameter
   to be set from the command line.
   The 8.1 guest kernel was vastly cut down from GENERIC and had no
   ISA devices. Booting GENERIC exposes a massive amount of random
   touching of i/o ports (hello syscons/vga/atkbdc).

bhyve/consport.c
dev/bvm/bvm_console.c
 - implement a simplistic signature for the bvm console by returning
   'bv' for an inw on the port. Also, set the priority of the console
   to CN_REMOTE if the signature was returned. This works better in
   an environment where multiple consoles are in the kernel (hello syscons)

bhyve/rtc.c
 - return 0 for the access to RTC_EQUIPMENT (yes, you syscons)

amd64/vmm/x86.c
          x86.h
 - hide a bunch more CPUID leaf 1 bits from the guest to prevent
   cpufreq drivers from probing.
   The next step will be to move CPUID handling completely into
   user-space. This will allow the full spectrum of changes from
   presenting a lowest-common-denominator CPU type/feature set, to
   exposing (almost) everything that the host can support.

Reviewed by:	neel
Obtained from:	NetApp
Avoid unnecessary sign extension when promoted to a 64-bit integer.

This was benign because the interruption info field is a 32-bit quantity and
the hardware guarantees that the upper 32-bits are all zeros. But it did make
reading the objdump output very confusing.
Fix a long standing bug in VMXCTX_GUEST_RESTORE().

There was an assumption by the "callers" of this macro that on "return" the
%rsp will be pointing to the 'vmxctx'. The macro was not doing this and thus
when trying to restore host state on an error from "vmlaunch" or "vmresume"
we were treating the memory locations on the host stack as 'struct vmxctx'.
This led to all sorts of weird bugs like double faults or invalid instruction
faults.

This bug is exposed by the -O2 option used to compile the kernel module. With
the -O2 flag the compiler will optimize the following piece of code:

	int loopstart = 1;
	...
	if (loopstart) {
		loopstart = 0;
		vmx_launch();
	} else
		vmx_resume();

into this:

	vmx_launch();

Since vmx_launch() and vmx_resume() are declared to be __dead2 functions the
compiler is free to do this. The compiler has no way to know that the
functions return indirectly through vmx_setjmp(). This optimization in turn
leads us to trigger the bug in VMXCTX_GUEST_RESTORE().

With this change we can boot a 8.1 guest on a 9.0 host.

Reported by: jhb@
Catch up with CURRENTs different timer usage compared to 8.1. A counter
value of 0 in rategen mode is equivalent to a max initial value.
The TSC is now correctly calibrated on a 9.0 guest.

Obtained from:	NetApp
IFC @ r222256
Add a 'show vmcs' DDB command to dump state about the current CPU's
current VMCS.
Missed this in the previous commit to add 'show vmcs': add opt_ddb.h as
a source file.
Some tweaks to the CPUID support:
- Don't always pass the cpuid request to the current CPU as some nodes
  we will emulate purely in software.
- Pass in the APIC ID of the virtual CPU so we can return the proper APIC
  ID.
- Always report a completely flat topology with no SMT or multicore.
- Report the CPUID2_HV feature and implement support for the 0x40000000
  CPUID level.
- Use existing constants from <machine/specialreg.h> when possible and
  use cpu_feature2 when checking for VMX support.
Allow access to the device's config area with any size i/o access at any
offset. This is now spec-compliant.
IFC @ r222830
IFC @ r223696 to pick up dfr's userboot
Get rid of redundant initialization of 'dmask'. It was being re-initialized
shortly afterwards.
'bhyveload' is a userspace FreeBSD loader that can load the kernel + metadata
inside a BHyVe-based virtual machine.

It is a thin wrapper on top of userboot.so which is a variant of the FreeBSD
loader packaged as a shared library. 'bhyveload' provides callbacks that are
utilized by userboot.so to do things like console i/o, disk i/o,
set virtual machine registers etc.

Thanks for Doug Rabson (dfr@) for making this happen.
IFC @ r224187
IFC @ r225592

sys/dev/bvm/bvm_console.c - move up to the new alt-break order.
Kernel configuration for a bhyve guest.