From 7d5c2ef35d0bd7eb90fac2f40225bcfb4a46421d Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Fri, 16 Aug 2019 17:16:33 +0100 Subject: pc: Don't make die-id mandatory unless necessary RH-Author: Eduardo Habkost Message-id: <20190816171633.26797-2-ehabkost@redhat.com> Patchwork-id: 90038 O-Subject: [RHEL-AV-8.1.0 qemu-kvm PATCH v2 1/1] pc: Don't make die-id mandatory unless necessary Bugzilla: 1741451 RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Danilo de Paula RH-Acked-by: Erik Skultety RH-Acked-by: Miroslav Rezanina We have this issue reported when using libvirt to hotplug CPUs: https://bugzilla.redhat.com/show_bug.cgi?id=1741451 Basically, libvirt is not copying die-id from query-hotpluggable-cpus, but die-id is now mandatory. We could blame libvirt and say it is not following the documented interface, because we have this buried in the QAPI schema documentation: > Note: currently there are 5 properties that could be present > but management should be prepared to pass through other > properties with device_add command to allow for future > interface extension. This also requires the filed names to be kept in > sync with the properties passed to -device/device_add. But I don't think this would be reasonable from us. We can just make QEMU more flexible and let die-id to be omitted when there's no ambiguity. This will allow us to keep compatibility with existing libvirt versions. Test case included to ensure we don't break this again. Fixes: commit 176d2cda0dee ("i386/cpu: Consolidate die-id validity in smp context") Signed-off-by: Eduardo Habkost --- Changes v1 -> v2: * v1 was "pc: Don't make CPU properties mandatory unless necessary" * Make only die-id optional (Igor Mammedov) Signed-off-by: Danilo C. L. de Paula --- hw/i386/pc.c | 8 ++++++ tests/acceptance/pc_cpu_hotplug_props.py | 35 ++++++++++++++++++++++++ 2 files changed, 43 insertions(+) create mode 100644 tests/acceptance/pc_cpu_hotplug_props.py diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 9ded0db80d..b3d2d1e88a 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -2622,6 +2622,14 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev, int max_socket = (ms->smp.max_cpus - 1) / smp_threads / smp_cores / pcms->smp_dies; + /* + * die-id was optional in QEMU 4.0 and older, so keep it optional + * if there's only one die per socket. + */ + if (cpu->die_id < 0 && pcms->smp_dies == 1) { + cpu->die_id = 0; + } + if (cpu->socket_id < 0) { error_setg(errp, "CPU socket-id is not set"); return; diff --git a/tests/acceptance/pc_cpu_hotplug_props.py b/tests/acceptance/pc_cpu_hotplug_props.py new file mode 100644 index 0000000000..08b7e632c6 --- /dev/null +++ b/tests/acceptance/pc_cpu_hotplug_props.py @@ -0,0 +1,35 @@ +# +# Ensure CPU die-id can be omitted on -device +# +# Copyright (c) 2019 Red Hat Inc +# +# Author: +# Eduardo Habkost +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, see . +# + +from avocado_qemu import Test + +class OmittedCPUProps(Test): + """ + :avocado: tags=arch:x86_64 + """ + def test_no_die_id(self): + self.vm.add_args('-nodefaults', '-S') + self.vm.add_args('-smp', '1,sockets=2,cores=2,threads=2,maxcpus=8') + self.vm.add_args('-cpu', 'qemu64') + self.vm.add_args('-device', 'qemu64-x86_64-cpu,socket-id=1,core-id=0,thread-id=0') + self.vm.launch() + self.assertEquals(len(self.vm.command('query-cpus')), 2) -- 2.20.1