From owner-freebsd-virtualization@freebsd.org  Sat Oct 21 21:07:49 2017
Return-Path: <owner-freebsd-virtualization@freebsd.org>
Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 06F0BE3A482;
 Sat, 21 Oct 2017 21:07:49 +0000 (UTC)
 (envelope-from mvoorhis@atom.mcvau.net)
Received: from atom.mcvau.net (unknown
 [IPv6:2602:100:615f:bdb7:5054:ff:fe0a:d781])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "atomvm.mcvau.net", Issuer "atomvm.mcvau.net" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id B053B6BDF0;
 Sat, 21 Oct 2017 21:07:48 +0000 (UTC)
 (envelope-from mvoorhis@atom.mcvau.net)
Received: from atom.mcvau.net (localhost [127.0.0.1])
 by atom.mcvau.net (8.15.2/8.15.2) with ESMTPS id v9LL7f4i027709
 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Sat, 21 Oct 2017 17:07:41 -0400 (EDT)
 (envelope-from mvoorhis@atom.mcvau.net)
Received: (from mvoorhis@localhost)
 by atom.mcvau.net (8.15.2/8.15.2/Submit) id v9LL7ejq021852;
 Sat, 21 Oct 2017 17:07:40 -0400 (EDT) (envelope-from mvoorhis)
From: Michael Voorhis <mvoorhis@mcvau.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
Message-ID: <23019.46875.929719.481108@atom.mcvau.net>
Date: Sat, 21 Oct 2017 17:07:39 -0400
To: Ian Lepore <ian@freebsd.org>
Cc: Boris Samorodov <bsam@passap.ru>, freebsd-current@FreeBSD.org,
 freebsd-virtualization@FreeBSD.org
Subject: Re: host, bhyve vm and ntpd
In-Reply-To: <1508523696.1383.75.camel@freebsd.org>
References: <2931f1cc-6574-b58d-4b94-5f77fa5cdb85@passap.ru>
 <1508512327.1383.55.camel@freebsd.org>
 <39bf2426-2edf-d485-7c81-519e931154be@passap.ru>
 <bf8eae88-ee44-58d5-bb3a-565a0314fdfe@passap.ru>
 <1508517160.1383.63.camel@freebsd.org>
 <76ff7afb-3d3a-96f6-1275-89472ff5683d@passap.ru>
 <1508522667.1383.69.camel@freebsd.org>
 <30992c14-7b78-ab9f-5693-931e6ca41f1b@passap.ru>
 <1508523696.1383.75.camel@freebsd.org>
X-Mailer: VM 8.2.0b under 25.3.1 (amd64-portbld-freebsd11.1)
X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=ham
 autolearn_force=no version=3.4.1
X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on atom.mcvau.net
X-BeenThere: freebsd-virtualization@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: "Discussion of various virtualization techniques FreeBSD supports."
 <freebsd-virtualization.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-virtualization>, 
 <mailto:freebsd-virtualization-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-virtualization/>
List-Post: <mailto:freebsd-virtualization@freebsd.org>
List-Help: <mailto:freebsd-virtualization-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization>, 
 <mailto:freebsd-virtualization-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 21 Oct 2017 21:07:49 -0000

Ian Lepore writes:
> Beyond that, I'm not sure what else to try. =A0It might be necessary =
to
> get some bhyve developers involved (I know almost nothing about it).

NTPD behaves more normally on uniprocessor VMs.

A FreeBSD bhyve-guest running on a freebsd host will select a
different timecounter depending on whether it is a multiprocessor or a
uniprocessor.  My uniprocessor bhyve-vm selected TSC-low as the best
timecounter in a uniprocessor.  NTP functions there as expected.

kern.timecounter.choice: TSC-low(1000) ACPI-fast(900) HPET(950) i8254(0=
) dummy(-1000000)
kern.timecounter.hardware: TSC-low

The very same VM, when given two total CPUs, selected HPET (if I
recall) and the timekeeping with NTPD was unreliable, with many
step-resets to the clock.