From 563d5929d5f28631999a32d2aab4e72e1bf2c323 Mon Sep 17 00:00:00 2001
From: Dave Cottlehuber <dch@FreeBSD.org>
Date: Sun, 30 May 2021 13:35:19 +0000
Subject: [PATCH] sysutils/kvmclock-kmod: new port - call for testing

Improved performance on KVM paravirtualised systems. Testing
welcomed; please report successes and issues to:

https://reviews.freebsd.org/D29733

kvmclock-kmod is experimental and currently under development. This port
provides an easy and quick method for users to test this code for early
testing, feedback and bug reports.

This driver enables FreeBSD to use a more efficient paravirtualized
hardware clock, instead of emulating one, or abusing hypervisor
interrupts, when running as a virtualized OS under Linux KVM
(Kernel-based Virtual Machine).

Reviewed by:	allanjude
Sponsored by:	Klara Inc.
Sponsored by:	SkunkWerks, GmbH
Differential Revision:	https://reviews.freebsd.org/D30459
PR:			216759
---
 sysutils/Makefile                  |  1 +
 sysutils/kvmclock-kmod/Makefile    | 25 +++++++++++++++++++++++++
 sysutils/kvmclock-kmod/distinfo    |  3 +++
 sysutils/kvmclock-kmod/pkg-descr   | 11 +++++++++++
 sysutils/kvmclock-kmod/pkg-message | 24 ++++++++++++++++++++++++
 5 files changed, 64 insertions(+)
 create mode 100644 sysutils/kvmclock-kmod/Makefile
 create mode 100644 sysutils/kvmclock-kmod/distinfo
 create mode 100644 sysutils/kvmclock-kmod/pkg-descr
 create mode 100644 sysutils/kvmclock-kmod/pkg-message

diff --git a/sysutils/Makefile b/sysutils/Makefile
index dda66170e644..98481ed67421 100644
--- a/sysutils/Makefile
+++ b/sysutils/Makefile
@@ -581,6 +581,7 @@
     SUBDIR += kshutdown
     SUBDIR += ksystemlog
     SUBDIR += kubectl
+    SUBDIR += kvmclock-kmod
     SUBDIR += lava
     SUBDIR += lbl-cf
     SUBDIR += lbl-hf
diff --git a/sysutils/kvmclock-kmod/Makefile b/sysutils/kvmclock-kmod/Makefile
new file mode 100644
index 000000000000..6a1c5ec2d222
--- /dev/null
+++ b/sysutils/kvmclock-kmod/Makefile
@@ -0,0 +1,25 @@
+PORTNAME=	kvmclock
+DISTVERSION=	0.0.0-a2
+CATEGORIES=	sysutils
+PKGNAMESUFFIX=	-kmod
+
+MAINTAINER=	dch@FreeBSD.org
+COMMENT=	Paravirtualized Linux KVM clock support
+
+LICENSE=	BSD2CLAUSE
+
+ONLY_FOR_ARCHS=	amd64 i386
+ONLY_FOR_ARCHS_REASON=	not yet tested for non-x86
+
+USES=		kmod uidfix
+KMOD=		kvmclock
+
+USE_GITHUB=	yes
+GH_ACCOUNT=	klarasystems
+
+PLIST_FILES=	${KMODDIR}/kvmclock.ko
+
+OPTIONS_DEFINE=	DEBUG
+OPTIONS_SUB=	yes
+
+.include <bsd.port.mk>
diff --git a/sysutils/kvmclock-kmod/distinfo b/sysutils/kvmclock-kmod/distinfo
new file mode 100644
index 000000000000..7e6f54fc3840
--- /dev/null
+++ b/sysutils/kvmclock-kmod/distinfo
@@ -0,0 +1,3 @@
+TIMESTAMP = 1621967719
+SHA256 (klarasystems-kvmclock-0.0.0-a2_GH0.tar.gz) = 1497f3eca5bc1f1d9708aa601f5fdbdea08852e16b6c9c1d55bc6d0262baf708
+SIZE (klarasystems-kvmclock-0.0.0-a2_GH0.tar.gz) = 7676
diff --git a/sysutils/kvmclock-kmod/pkg-descr b/sysutils/kvmclock-kmod/pkg-descr
new file mode 100644
index 000000000000..7eca429ebc59
--- /dev/null
+++ b/sysutils/kvmclock-kmod/pkg-descr
@@ -0,0 +1,11 @@
+Development version of kvmclock FreeBSD driver for virtual machines.
+
+References and prior art:
+
+https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/virtualization_deployment_and_administration_guide/chap-kvm_guest_timing_management
+https://www.vmware.com/files/pdf/techpaper/Timekeeping-In-VirtualMachines.pdf
+http://oliveryang.net/2015/09/pitfalls-of-TSC-usage/#33-tsc-emulation-on-different-hypervisors
+https://reviews.freebsd.org/D29531
+https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=216759
+
+WWW: https://reviews.freebsd.org/D29733
diff --git a/sysutils/kvmclock-kmod/pkg-message b/sysutils/kvmclock-kmod/pkg-message
new file mode 100644
index 000000000000..d410eecdba03
--- /dev/null
+++ b/sysutils/kvmclock-kmod/pkg-message
@@ -0,0 +1,24 @@
+[
+{ type: install
+  message: <<EOM
+kvmclock-kmod is experimental and currently under development. This port
+provides an easy and quick method for users to test this code for early
+testing, feedback and bug reports.
+
+This driver enables FreeBSD to use a more efficient paravirtualized
+hardware clock, instead of emulating one, or abusing hypervisor
+interrupts, when running as a virtualized OS under Linux KVM
+(Kernel-based Virtual Machine).
+
+Usage:
+
+# kldload kvmclock
+# sysctl kern.timecounter
+kern.timecounter.choice: kvmclock(975) i8254(0) ...
+kern.timecounter.hardware: kvmclock
+...
+
+Please report successes and issues to: https://reviews.freebsd.org/D29733
+EOM
+}
+]