sys: 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

sys: Remove $FreeBSD$: one-line .c pattern

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

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

vmm: fix use after free in ppt_detach()

The vmm module destroys the host_domain before unloading the ppt module
causing a use after free. This can happen when kldunload'ing vmm.

Reviewed by: markj, jhb
Differential Revision: https://reviews.freebsd.org/D38072

vmm: Make iommu ops tables const

While here, use designated initializers and rename some AMD iommu method
implementations to match the corresponding op names. No functional
change intended.

Reviewed by: grehan
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31462

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (4 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked). Use it in
preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Reviewed by: kib
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D23625
X-Generally looks fine: jhb

vmm: Add Hygon Dhyana support.

Submitted by: Pu Wen <puwen@hygon.cn>
Discussed with: grehan
Reviewed by: jhb (previous version)
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23553

Extract eventfilter declarations to sys/_eventfilter.h

This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.

EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).

As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions. The remainder of the patch addresses
adding appropriate includes to fix those files.

LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).

No functional change (intended). Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.

sys/amd64: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Rework pass through changes in r305485 to be safer.

Specifically, devices that do not support PCI-e FLR and were not
gracefully shutdown by the guest OS could continue to issue DMA
requests after the VM was terminated. The changes in r305485 meant
that those DMA requests were completed against the host's memory which
could result in random memory corruption. Instead, leave ppt devices
that are not attached to a VM disabled in the IOMMU and only restore
the devices to the host domain if the ppt(4) driver is detached from a
device.

As an added safety belt, disable busmastering for a pass-through device
when before adding it to the host domain during ppt(4) detach.

PR: 222937
Tested by: Harry Schmalzbauer <freebsd@omnilan.de>
Reviewed by: grehan
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D12661

Update the I/O MMU in bhyve when PCI devices are added and removed.

When the I/O MMU is active in bhyve, all PCI devices need valid entries
in the DMAR context tables. The I/O MMU code does a single enumeration
of the available PCI devices during initialization to add all existing
devices to a domain representing the host. The ppt(4) driver then moves
pass through devices in and out of domains for virtual machines as needed.
However, when new PCI devices were added at runtime either via SR-IOV or
HotPlug, the I/O MMU tables were not updated.

This change adds a new set of EVENTHANDLERS that are invoked when PCI
devices are added and deleted. The I/O MMU driver in bhyve installs
handlers for these events which it uses to add and remove devices to
the "host" domain.

Reviewed by: imp
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D7667

Leave ppt devices in the host domain when they are not attached to a VM.

This allows a pass through device to be reset to a normal device driver
on the host and reused on the host. ppt devices are now always active in
some I/O MMU domain when the I/O MMU is active, either the host domain
or the domain of a VM they are attached to.

Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D7666

Enable I/O MMU when PCI pass through is first used.

Rather than enabling the I/O MMU when the vmm module is loaded,
defer initialization until the first attempt to pass a PCI device
through to a guest. If the I/O MMU fails to initialize or is not
present, than fail the attempt to pass a PCI device through to a
guest.

The hw.vmm.force_iommu tunable has been removed since the I/O MMU is
no longer enabled during boot. However, the I/O MMU support can be
disabled by setting the hw.vmm.iommu.enable tunable to 0 to prevent
use of the I/O MMU on any systems where it is buggy.

Reviewed by: grehan
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D7448

Re-write bhyve's I/O MMU handling in terms of PCI RID.

Reviewed by: neel
MFC after: 2 months
Sponsored by: Sandvine Inc.

Revert PCI RID changes.

My PCI RID changes somehow got intermixed with my PCI ARI patch when I
committed it. I may have accidentally applied a patch to a non-clean
working tree. Revert everything while I figure out what went wrong.

Pointy hat to: rstone

Re-write bhyve's I/O MMU handling in terms of PCI RIDs

Reviewed by: neel
Sponsored by: Sandvine Inc

There is no need to initialize the IOMMU if no passthru devices have been
configured for bhyve to use.

Suggested by: grehan@

Allocate memory pages for the guest from the host's free page queue.

It is no longer necessary to hard-partition the memory between the host
and guests at boot time.

Import of bhyve hypervisor and utilities, part 1.
vmm.ko - kernel module for VT-x, VT-d and hypervisor control
bhyve - user-space sequencer and i/o emulation
vmmctl - dump of hypervisor register state
libvmm - front-end to vmm.ko chardev interface

bhyve was designed and implemented by Neel Natu.

Thanks to the following folk from NetApp who helped to make this available:
Joe CaraDonna
Peter Snyder
Jeff Heller
Sandeep Mann
Steve Miller
Brian Pawlowski