From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:54653)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pkrempa@redhat.com>) id 1b8UB7-0006qm-HC
	for qemu-devel@nongnu.org; Thu, 02 Jun 2016 11:05:01 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pkrempa@redhat.com>) id 1b8UB1-0003MN-G3
	for qemu-devel@nongnu.org; Thu, 02 Jun 2016 11:04:57 -0400
Date: Thu, 2 Jun 2016 17:05:06 +0200
From: Peter Krempa <pkrempa@redhat.com>
Message-ID: <20160602150506.GF5194@andariel.pipo.sk>
References: <1464799050-11002-1-git-send-email-imammedo@redhat.com>
	<1464799050-11002-5-git-send-email-imammedo@redhat.com>
	<20160601184620.GE13503@thinpad.lan.raisama.net>
	<20160602142222.307ec4ee@nial.brq.redhat.com>
	<20160602145322.GG19055@thinpad.lan.raisama.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <20160602145322.GG19055@thinpad.lan.raisama.net>
Subject: Re: [Qemu-devel] [PATCH RFC 4/8] target-i386: cpu: consolidate
 calls of object_property_parse() in x86_cpu_parse_featurestr
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>, qemu-devel@nongnu.org, peter.maydell@linaro.org, pbonzini@redhat.com, rth@twiddle.net, blauwirbel@gmail.com, mark.cave-ayland@ilande.co.uk, qemu-arm@nongnu.org, libvir-list@redhat.com, Jiri Denemark <jdenemar@redhat.com>

On Thu, Jun 02, 2016 at 11:53:22 -0300, Eduardo Habkost wrote:
> (CCing libvirt folks)
>=20
> BTW:
>=20
> On Thu, Jun 02, 2016 at 02:22:22PM +0200, Igor Mammedov wrote:
> [...]
> > >         /* Special cases: */
> > >         if (!strcmp(name, "xlevel")) {
> > >             numvalue =3D strtoul(val, &err, 0);
> > >             if (!*val || *err) {
> > >                 error_setg(errp, "bad numerical value %s", val);
> > >                 return;
> > >             }
> > >             if (numvalue < 0x80000000) {
> > >                 error_report("xlevel value shall always be >=3D 0x800=
00000"
> > >                              ", fixup will be removed in future versi=
ons");
> > >                 numvalue +=3D 0x80000000;
> > >             snprintf(num, sizeof(num), "%" PRIu32, numvalue);
> > >             val =3D num;
> [...]
> > >         } else if (!strcmp(name, "hv-spinlocks")) {
> > >             const int min =3D 0xFFF;
> > >=20
> > >             numvalue =3D strtoul(val, &err, 0);
> > >             if (!*val || *err) {
> > >                 error_setg(errp, "bad numerical value %s", val);
> > >                 return;
> > >             }
> > >             if (numvalue < min) {
> > >                 error_report("hv-spinlocks value shall always be >=3D=
 0x%x"
> > >                              ", fixup will be removed in future versi=
ons",
> > >                              min);
> > >                 numvalue =3D min;
> > >             }
>=20
> Those "fixup will be removed in future versions" warnings are
> present since QEMU 1.7. Assuming that libvirt never allowed those
> invalid values to be used in the configuration (did it?), I
> believe we can safely remove the hv-spinlocks and xlevel fixups
> in QEMU 2.7.

I couldn't find anything regarding xlevel (so we might actually not
support it at all), but we indeed do limit the hv_spinlock count:


                if (def->hyperv_spinlocks < 0xFFF) {
                    virReportError(VIR_ERR_XML_ERROR, "%s",
                                   _("HyperV spinlock retry count must be "
                                     "at least 4095"));
                    goto error;
                }

Peter