usr.sbin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

bhyve: Remove vmctx argument from PCI device model methods.

Most of these arguments were unused. Device models which do need
access to the vmctx in one of these methods can obtain it from the
pi_vmctx member of the pci_devinst argument instead.

Reviewed by: corvink, markj
Differential Revision: https://reviews.freebsd.org/D38096

bhyve: Annotate unused function parameters

MFC after: 1 week

bhyve: Use designated initializers for virtio_consts tables

This is easier to read and addresses some compiler warnings.

One might expect these tables to be read-only but it seems that the
snapshot/restore code may modify them.

MFC after: 2 weeks

bhyve: Mark variables and functions as static where appropriate

Mark them const as well when it makes sense to do so. No functional
change intended.

MFC after: 1 week
Sponsored by: The FreeBSD Foundation

bhyve: clean up trailing whitespaces

Clean up trailing whitespaces. No functional changes.

Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D33681

bhyve: Fix vq_getchain() error handling bugs in various device models

Reviewed by: grehan, khng
Approved by: so
Security: CVE-2021-29631
Security: FreeBSD-SA-21:13.bhyve

bhyve: fix regression in legacy virtio-9p config parsing

Commit 621b5090487de9fed1b503769702a9a2a27cc7bb introduced a regression
in legacy virtio-9p config parsing by not initializing *sharename to
NULL. As a result, "sharename != NULL" check in the first iteration fails
and bhyve exits with "virtio-9p: more than one share name given".

Fix by adding NULL back.

Approved by: grehan

bhyve: change vq_getchain to return iovecs in both directions

The old prototype requires callers to inspect flags of each descriptors
to get the starting position of host-writable iovecs.

vq_getchain() is changed to return a virtio request with the number of
host-readable iovecs and host-writable iovecs instead. Callers can avoid
boilerplate code of getting the start offset of host-writable iovecs.

Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Reviewed by: afedorov
Approved by: philip (mentor)
Differential Revision: https://reviews.freebsd.org/D29433

Refactor configuration management in bhyve.

Replace the existing ad-hoc configuration via various global variables
with a small database of key-value pairs. The database supports
heirarchical keys using a MIB-like syntax to name the path to a given
key. Values are always stored as strings. The API used to manage
configuation values does include wrappers to handling boolean values.
Other values use non-string types require parsing by consumers.

The configuration values are stored in a tree using nvlists. Leaf
nodes hold string values. Configuration values are permitted to
reference other configuration values using '%(name)'. This permits
constructing template configurations.

All existing command line arguments now set configuration values. For
devices, the "-s" option parses its option argument to generate a list
of key-value pairs for the given device.

A new '-o' command line option permits setting an individual
configuration variable. The key name is always given as a full path
of dot-separated components.

A new '-k' command line option parses a simple configuration file.
This configuration file holds a flat list of 'key=value' lines where
the 'key' is the full path of a configuration variable. Lines
starting with a '#' are comments.

In general, bhyve starts by parsing command line options in sequence
and applying those settings to configuration values. Once this is
complete, bhyve then begins initializing its state based on the
configuration values. This means that subsequent configuration
options or files may override or supplement previously given settings.

A special 'config.dump' configuration value can be set to true to help
debug configuration issues. When this value is set, bhyve will print
out the configuration variables as a flat list of 'key=value' lines.

Most command line argments map to a single configuration variable,
e.g. '-w' sets the 'x86.strictmsr' value to false. A few command
line arguments have less obvious effects:

- Multiple '-p' options append their values (as a comma-seperated
list) to "vcpu.N.cpuset" values (where N is a decimal vcpu number).

- For '-s' options, a pci.<bus>.<slot>.<function> node is created.
The first argument to '-s' (the device type) is used as the value of
a "device" variable. Additional comma-separated arguments are then
parsed into 'key=value' pairs and used to set additional variables
under the device node. A PCI device emulation driver can provide
its own hook to override the parsing of the additonal '-s' arguments
after the device type.

After the configuration phase as completed, the init_pci hook
then walks the "pci.<bus>.<slot>.<func>" nodes. It uses the
"device" value to find the device model to use. The device
model's init routine is passed a reference to its nvlist node
in the configuration tree which it can query for specific
variables.

The result is that a lot of the string parsing is removed from
the device models and centralized. In addition, adding a new
variable just requires teaching the model to look for the new
variable.

- For '-l' options, a similar model is used where the string is
parsed into values that are later read during initialization.
One key note here is that the serial ports use the commonly
used lowercase names from existing documentation and examples
(e.g. "lpc.com1") instead of the uppercase names previously
used internally in bhyve.

Reviewed by: grehan
MFC after: 3 months
Differential Revision: https://reviews.freebsd.org/D26035

bhyve: virtio shares definitions between sys/dev/virtio

Definitions inside usr.sbin/bhyve/virtio.h are thrown away.
Definitions in sys/dev/virtio are used instead.

This reduces code duplication.

Sponsored by: The FreeBSD Foundation
Reviewed by: grehan
Approved by: philip (mentor)
Differential Revision: https://reviews.freebsd.org/D29084

Add virtio-9p (aka VirtFS) filesystem sharing to bhyve.

VirtFS allows sharing an arbitrary directory tree between bhyve virtual
machine and the host. Current implementation has a fairly complete support
for 9P2000.L protocol, except for the extended attribute support. It has
been verified to work with the qemu-kvm hypervisor.

Reviewed by: rgrimes, emaste, jhb, trasz
Approved by: trasz (mentor)
MFC after: 1 month
Relnotes: yes
Sponsored by: Conclusive Engineering (development), vStack.com (funding)
Differential Revision: https://reviews.freebsd.org/D10335