bhyveload(8): document some SECURITY CONSIDERATIONS

The situation is improved now that we're running in a sandbox, but there
is still some host machine access that could be concerning depending on
the context. These concerns may be somewhat mitigated by the fact that
the host machine usually provides the loader binary, even when the guest
image is providing the loader scripts -- they only bring the lua
scripts, and they have to be able to execute arbitrary syscalls rather
than the interfaces provided by libsa(3).

Reviewed by: jhb, markj
Differential Revision: https://reviews.freebsd.org/D43299

Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

bhyve: improve memory size documentation

A couple of minor memory size option related nits:

- use common name 'memsize' (instead of 'max-size' or just 'size')
- bhyve: update usage with memsize unit suffix, drop legacy "MB"
unit
- bhyveload: update usage with memsize unit suffix
- bhyve(8): document default size
- bhyveload(8): use memsize formatting like it's done
in bhyve(8)

Reviewed by: wblock, grehan
Approved by: re (kib), wblock, grehan
Differential Revision: https://reviews.freebsd.org/D6952

Add option -C to have the guest memory included in core files.
This aids in debugging OS loaders.

Add option -l for specifying which OS loader to dlopen(3). By default
this is /boot/userboot.so. This option allows for the development and
use of other OS loaders.

Fix issues detected by 'mandoc -Tlint bhyveload.8'

Pointed out by: wblock
Differential Revision: https://reviews.freebsd.org/D2762

Restructure memory allocation in bhyve to support "devmem".

devmem is used to represent MMIO devices like the boot ROM or a VESA framebuffer
where doing a trap-and-emulate for every access is impractical. devmem is a
hybrid of system memory (sysmem) and emulated device models.

devmem is mapped in the guest address space via nested page tables similar
to sysmem. However the address range where devmem is mapped may be changed
by the guest at runtime (e.g. by reprogramming a PCI BAR). Also devmem is
usually mapped RO or RW as compared to RWX mappings for sysmem.

Each devmem segment is named (e.g. "bootrom") and this name is used to
create a device node for the devmem segment (e.g. /dev/vmm/testvm.bootrom).
The device node supports mmap(2) and this decouples the host mapping of
devmem from its mapping in the guest address space (which can change).

Reviewed by: tychon
Discussed with: grehan
Differential Revision: https://reviews.freebsd.org/D2762
MFC after: 4 weeks

Sort command flags in usage output and the manpages.

use .Mt to mark up email addresses consistently (part2)

PR: 191174
Submitted by: Franco Fichtner <franco@lastsummer.de>

o Fix typo, sort .Xrs.

PR: docs/186191
Submitted by: Andrew (typo fix)
MFC after: 1 week

mdoc: quote string properly.

Allow bhyve and bhyveload to attach to tty devices.

bhyveload: introduce the -c <device> parameter
to select a tty for output (or "stdio")

bhyve: allow the puc and lpc-com backends to
accept a tty in addition to "stdio"

When used in conjunction with the null-modem device,
nmdm(4), this allows attach/detach to the guest console
and multiple concurrent serial ports. kgdb on a serial
port is now functional.

Reviewed by: neel
Requested by: Almost everyone that has used bhyve
MFC after: 10.0

Add an option to bhyveload(8) that allows setting a loader environment variable
from the command line.

The option syntax is "-e <name=value>". It may be used multiple times to set
multiple environment variables.

Reviewed by: grehan
Requested by: alfred

Fix missing .

Approved by: re (blanket)

Parse the memory size parameter using expand_number() to allow specifying
the memory size more intuitively (e.g. 512M, 4G etc).

Submitted by: rodrigc
Reviewed by: grehan
Approved by: re (blanket)

mdoc: remove superfluous paragraph macro.

Simplify the assignment of memory to virtual machines by requiring a single
command line option "-m <memsize in MB>" to specify the memory size.

Prior to this change the user needed to explicitly specify the amount of
memory allocated below 4G (-m <lowmem>) and the amount above 4G (-M <highmem>).

The "-M" option is no longer supported by 'bhyveload' and 'bhyve'.

The start of the PCI hole is fixed at 3GB and cannot be directly changed
using command line options. However it is still possible to change this in
special circumstances via the 'vm_set_lowmem_limit()' API provided by
libvmmapi.

Submitted by: Dinakar Medavaram (initial version)
Reviewed by: grehan
Obtained from: NetApp

Remove EOL whitespace.

Minor mdoc fixes.

Add the 'bhyveload(8)' man page.

Obtained from: NetApp
Reviewed by: grehan