From b62f8e7394b20d38b22708b7bb879e32ba1fcaec Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Mon, 1 Aug 2016 08:12:06 +0200 Subject: [PATCH 66/99] pc: Enforce adding CPUs contiguously and removing them in opposite order RH-Author: Igor Mammedov Message-id: <1470039143-24450-62-git-send-email-imammedo@redhat.com> Patchwork-id: 71677 O-Subject: [RHEV-7.3 qemu-kvm-rhev PATCH 61/78] pc: Enforce adding CPUs contiguously and removing them in opposite order Bugzilla: 1087672 RH-Acked-by: Marcel Apfelbaum RH-Acked-by: David Gibson RH-Acked-by: Eduardo Habkost It will still allow us to use cpu_index as migration instance_id since when CPUs are added contiguously (from the first to the last) and removed in opposite order, cpu_index stays stable and it's reproducible on destination side. While there is work in progress to support migration when there are holes in cpu_index range resulting from out-of-order plug or unplug, this patch is intended as an interim solution until cpu_index usage is cleaned up. As result of this patch it would be possible to plug/unplug CPUs, but in limited order that doesn't break migration. Signed-off-by: Igor Mammedov Reviewed-by: Michael S. Tsirkin Signed-off-by: Eduardo Habkost (cherry picked from commit 4da7faaeb0c7dd3f7f233165d336c878f78fd1eb) Signed-off-by: Miroslav Rezanina --- hw/i386/pc.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 2ea79bf..addd29d 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1743,6 +1743,23 @@ static void pc_cpu_unplug_request_cb(HotplugHandler *hotplug_dev, goto out; } + if (idx < pcms->possible_cpus->len - 1 && + pcms->possible_cpus->cpus[idx + 1].cpu != NULL) { + X86CPU *cpu; + + for (idx = pcms->possible_cpus->len - 1; + pcms->possible_cpus->cpus[idx].cpu == NULL; idx--) { + ;; + } + + cpu = X86_CPU(pcms->possible_cpus->cpus[idx].cpu); + error_setg(&local_err, "CPU [socket-id: %u, core-id: %u," + " thread-id: %u] should be removed first", + cpu->socket_id, cpu->core_id, cpu->thread_id); + goto out; + + } + hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev); hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err); @@ -1840,6 +1857,23 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev, return; } + if (idx != 0 && pcms->possible_cpus->cpus[idx - 1].cpu == NULL) { + PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms); + + for (idx = 1; pcms->possible_cpus->cpus[idx].cpu != NULL; idx++) { + ;; + } + + x86_topo_ids_from_apicid(pcms->possible_cpus->cpus[idx].arch_id, + smp_cores, smp_threads, &topo); + + if (!pcmc->legacy_cpu_hotplug) { + error_setg(errp, "CPU [socket: %u, core: %u, thread: %u] should be" + " added first", topo.pkg_id, topo.core_id, topo.smt_id); + return; + } + } + /* if 'address' properties socket-id/core-id/thread-id are not set, set them * so that query_hotpluggable_cpus would show correct values */ -- 1.8.3.1