Date: Fri, 4 Mar 2022 13:35:48 -0500 From: Shawn Webb <shawn.webb@hardenedbsd.org> To: Mark Johnston <markj@freebsd.org> Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 84369dd52369 - main - x86: Probe the TSC frequency earlier Message-ID: <20220304183548.r335ihm5wyjol7dd@mutt-hbsd> In-Reply-To: <YiJa7jmEeRrAlc0S@nuc> References: <202203011439.221EdtpY038505@gitrepo.freebsd.org> <20220304142447.bmo7r6syd6gsunnt@mutt-hbsd> <YiIsshB5MgS6QdU3@nuc> <20220304175226.avi2r57dvjfeyr7w@mutt-hbsd> <20220304181529.isvkyyx3qwcbt6v7@mutt-hbsd> <YiJa7jmEeRrAlc0S@nuc>
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--725rklmhpen4lukn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 04, 2022 at 01:31:10PM -0500, Mark Johnston wrote: > On Fri, Mar 04, 2022 at 01:15:29PM -0500, Shawn Webb wrote: > > On Fri, Mar 04, 2022 at 12:52:26PM -0500, Shawn Webb wrote: > > > On Fri, Mar 04, 2022 at 10:13:54AM -0500, Mark Johnston wrote: > > > > On Fri, Mar 04, 2022 at 09:24:47AM -0500, Shawn Webb wrote: > > > > > On Tue, Mar 01, 2022 at 02:39:55PM +0000, Mark Johnston wrote: > > > > > > The branch main has been updated by markj: > > > > > >=20 > > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=3D84369dd52369cbae= 28970dca20a53d3de1719907 > > > > > >=20 > > > > > > commit 84369dd52369cbae28970dca20a53d3de1719907 > > > > > > Author: Mark Johnston <markj@FreeBSD.org> > > > > > > AuthorDate: 2022-03-01 14:39:35 +0000 > > > > > > Commit: Mark Johnston <markj@FreeBSD.org> > > > > > > CommitDate: 2022-03-01 14:39:35 +0000 > > > > > >=20 > > > > > > x86: Probe the TSC frequency earlier > > > > > > =20 > > > > > > This lets us use the TSC to implement early DELAY, limiting= the use of > > > > > > the sometimes-unreliable 8254 PIT. > > > > > > =20 > > > > > > PR: 262155 > > > > > > Reviewed by: emaste > > > > > > Tested by: emaste, mike tancsa <mike@sentex.net>, Stef= an Hegnauer <stefan.hegnauer@gmx.ch> > > > > > > MFC after: 1 month > > > > > > Sponsored by: The FreeBSD Foundation > > > > > > Differential Revision: https://reviews.freebsd.org/D34367 > > > > > > --- > > > > > > sys/amd64/amd64/machdep.c | 14 +++++- > > > > > > sys/i386/i386/machdep.c | 11 ++++- > > > > > > sys/x86/include/clock.h | 3 +- > > > > > > sys/x86/isa/clock.c | 4 +- > > > > > > sys/x86/x86/tsc.c | 123 +++++++++++++++++++++++++-----= ---------------- > > > > > > 5 files changed, 94 insertions(+), 61 deletions(-) > > > > >=20 > > > > > Hey Mark, > > > > >=20 > > > > > Something about this commit breaks booting in Hyper-V. Reverting = this > > > > > particular commit makes Hyper-V happy again. > > > >=20 > > > > The patch below might be sufficient. I'll test it in Azure but it'= ll > > > > take me some time. > > > >=20 > > > > diff --git a/sys/x86/x86/delay.c b/sys/x86/x86/delay.c > > > > index c767250954da..95b994b15f81 100644 > > > > --- a/sys/x86/x86/delay.c > > > > +++ b/sys/x86/x86/delay.c > > > > @@ -89,7 +89,7 @@ delay_tc(int n) > > > > return (1); > > > > } > > > > tc =3D timecounter; > > > > - if (tc->tc_quality <=3D 0) > > > > + if (tc =3D=3D NULL || tc->tc_quality <=3D 0) > > > > return (0); > > > > func =3D tc->tc_get_timecount; > > > > mask =3D tc->tc_counter_mask; > > >=20 > > > Great! I'll give this patch a try and report back. > >=20 > > The proposed patch did not result in successful boot. >=20 > Ok, I forgot about the dummy timecounter, so that patch did nothing. > Can you try this one instead, please? https://reviews.freebsd.org/D34444 >=20 > I wasn't able to reproduce any problems on Azure, but there HyperV > provides an emulated 8254 timer. Interesting. It looks like I don't have the option to switch timers in Hyper-V on Win11 on an Intel NUC. FWIW, it's a gen2 VM. If you have any suggestions on how I could help debug this, please let me know. Thanks, --=20 Shawn Webb Cofounder / Security Engineer HardenedBSD https://git.hardenedbsd.org/hardenedbsd/pubkeys/-/raw/master/Shawn_Webb/03A= 4CBEBB82EA5A67D9F3853FF2E67A277F8E1FA.pub.asc --725rklmhpen4lukn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEA6TL67gupaZ9nzhT/y5nonf44foFAmIiXAIACgkQ/y5nonf4 4fr2sw/8D1gsDCL9sAWyDYzmEeqSeT2MU7Pcqi7j5tnBNrrnRUBc0MZnPBFmAj2t k5Bq6q9+ESjRJhn80iDpWyp/drpNiBNm8VK2WPYMvSffeaDCH+60CSCtD8TkDnp5 IWL072Su1fXEpifhWhommqKld2/rqaa242eCXzbukVzNY+w66lAvNZDcqCdiiBZI mVlOyeU6FZenzrHUUHQjmsgh2dGibQnwCF3qk+78K/AEC4dTZKP3VP0V9ObTMD69 e5RbzA06OWIqm4w08rp2ZTYtcybG7CgRjMh31RAOW8ldSL3r6lt4XkXyH/hkkeb2 5+/3evR1jA9ng0Wj9rr3rINQxTc7x3BMwcOf0pB4gR6IWYrow+L9fudQTgcXY2FX crtPeMj6viTBM91dD8LJ4RkcER2yVXqIdHlKadq1lr/DkNmd/equbbgRWHADl+d4 KqI6SYZQfJDjrwloBCM+DJUYFQsR2UnaJOFqVB3BGjf9eV425TPZ6tMg/GYgodhR 9CSFenWkqNL22xVRRGbk3gAQ1PfJB/3f6MCmqXQ4jUCajPTND52cTrsUxVE83niL xF8apmMz02SXt9TjmWI3PeZNehpdWlEfw5JycJ29irzrG8eieIaSoARIZvKEibuC jahWKdH+CB/whPaO/pOb6gMKih7gYVeIpiLDvHc9CoZUaLPau34= =j3JG -----END PGP SIGNATURE----- --725rklmhpen4lukn--
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