From nobody Sun Feb 8 17:48:04 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1539893238931375.31402652165093; Thu, 18 Oct 2018 13:07:18 -0700 (PDT) Received: from localhost ([::1]:44270 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gDEZY-0000Qw-9S for importer@patchew.org; Thu, 18 Oct 2018 16:07:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38429) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gDEXK-0007TJ-Rc for qemu-devel@nongnu.org; Thu, 18 Oct 2018 16:04:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gDEXJ-0006yo-SS for qemu-devel@nongnu.org; Thu, 18 Oct 2018 16:04:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35526) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gDEXE-0006vm-7g; Thu, 18 Oct 2018 16:04:44 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 47E823001C5F; Thu, 18 Oct 2018 20:04:43 +0000 (UTC) Received: from localhost (ovpn-117-52.phx2.redhat.com [10.3.117.52]) by smtp.corp.redhat.com (Postfix) with ESMTP id C6F9C68B2A; Thu, 18 Oct 2018 20:04:38 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell , qemu-devel@nongnu.org Date: Thu, 18 Oct 2018 17:03:39 -0300 Message-Id: <20181018200422.4358-3-ehabkost@redhat.com> In-Reply-To: <20181018200422.4358-1-ehabkost@redhat.com> References: <20181018200422.4358-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Thu, 18 Oct 2018 20:04:43 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 02/45] vl.c deprecate incorrect CPUs topology X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Michael S. Tsirkin" , libvir-list@redhat.com, Jason Wang , Mark Cave-Ayland , Markus Armbruster , Max Filippov , "Edgar E. Iglesias" , Rob Herring , Alexander Graf , Richard Henderson , Artyom Tarasenko , Eduardo Habkost , Alistair Francis , qemu-arm@nongnu.org, Paolo Bonzini , David Gibson , Xiao Guangrong , Peter Crosthwaite , Michael Walle , qemu-ppc@nongnu.org, Aleksandar Markovic , Igor Mammedov , Aurelien Jarno Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Igor Mammedov -smp [cpus],sockets/cores/threads[,maxcpus] should describe topology so that total number of logical CPUs [sockets * cores * threads] would be equal to [maxcpus], however historically we didn't have such check in QEMU and it is possible to start VM with an invalid topology. Deprecate invalid options combination so we can make sure that the topology VM started with is always correct in the future. Users with an invalid sockets/cores/threads/maxcpus values should fix their CLI to make sure that [sockets * cores * threads] =3D=3D [maxcpus] Signed-off-by: Igor Mammedov Reviewed-by: Andrew Jones Reviewed-by: Eduardo Habkost Message-Id: <1536836762-273036-2-git-send-email-imammedo@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Eduardo Habkost Reviewed-by: David Gibson --- vl.c | 7 +++++++ qemu-deprecated.texi | 12 ++++++++++++ 2 files changed, 19 insertions(+) diff --git a/vl.c b/vl.c index 4e25c78bff..027d04c7ca 100644 --- a/vl.c +++ b/vl.c @@ -1235,6 +1235,13 @@ static void smp_parse(QemuOpts *opts) exit(1); } =20 + if (sockets * cores * threads !=3D max_cpus) { + warn_report("Invalid CPU topology deprecated: " + "sockets (%u) * cores (%u) * threads (%u) " + "!=3D maxcpus (%u)", + sockets, cores, threads, max_cpus); + } + smp_cpus =3D cpus; smp_cores =3D cores; smp_threads =3D threads; diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index 11b870c5c1..5d2d7a3588 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -86,6 +86,18 @@ for these file types is 'host_cdrom' or 'host_device' as= appropriate. The @option{name} parameter of the @option{-net} option is a synonym for the @option{id} parameter, which should now be used instead. =20 +@subsection -smp (invalid topologies) (since 3.1) + +CPU topology properties should describe whole machine topology including +possible CPUs. + +However, historically it was possible to start QEMU with an incorrect topo= logy +where @math{@var{n} <=3D @var{sockets} * @var{cores} * @var{threads} < @va= r{maxcpus}}, +which could lead to an incorrect topology enumeration by the guest. +Support for invalid topologies will be removed, the user must ensure +topologies described with -smp include all possible cpus, i.e. + @math{@var{sockets} * @var{cores} * @var{threads} =3D @var{maxcpus}}. + @section QEMU Machine Protocol (QMP) commands =20 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0) --=20 2.18.0.rc1.1.g3f1ff2140