From patchwork Fri Apr 9 20:22:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 12195005 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46185C433B4 for ; Fri, 9 Apr 2021 20:26:19 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC0F7610A8 for ; Fri, 9 Apr 2021 20:26:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC0F7610A8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50278 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lUxhp-00038Z-W2 for qemu-devel@archiver.kernel.org; Fri, 09 Apr 2021 16:26:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52604) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lUxec-0008WO-UK for qemu-devel@nongnu.org; Fri, 09 Apr 2021 16:22:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42272) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lUxeb-0004BM-8u for qemu-devel@nongnu.org; Fri, 09 Apr 2021 16:22:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617999776; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=A831zHdvpuQd0VH2Tp3eQkFBYyVatf0BAWnK+8L2BNA=; b=AuTBFNk+/PHhQodcMwrrQ1VlvMv4FQsTwcOYA6wSp7nTBq9KAv1NPuVuLBlG7RojV18L/7 cU+hsrQnpd6OH0kJH4J/VNVDqAejVaEA4W9//iO1j0CABC8x8pbXj/1D53dGcrQpWwgqwe S5T24MCWGo2Wq/7p+YzH/5HYNdv6sXo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-234-BjolE5WMMvuo7ykW875xQA-1; Fri, 09 Apr 2021 16:22:54 -0400 X-MC-Unique: BjolE5WMMvuo7ykW875xQA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5A83018B614E; Fri, 9 Apr 2021 20:22:53 +0000 (UTC) Received: from localhost (ovpn-118-57.rdu2.redhat.com [10.10.118.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 24C2E60916; Fri, 9 Apr 2021 20:22:53 +0000 (UTC) From: Eduardo Habkost To: qemu-devel@nongnu.org, Peter Maydell Subject: [PULL 2/2] cpu/core: Fix "help" of CPU core device types Date: Fri, 9 Apr 2021 16:22:46 -0400 Message-Id: <20210409202246.1857179-3-ehabkost@redhat.com> In-Reply-To: <20210409202246.1857179-1-ehabkost@redhat.com> References: <20210409202246.1857179-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , Eduardo Habkost , Richard Henderson , Greg Kurz , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Greg Kurz Calling qdev_get_machine() from a QOM instance_init function is fragile because we can't be sure the machine object actually exists. And this happens to break when passing ",help" on the command line to get the list of properties for a CPU core device types : $ ./qemu-system-ppc64 -device power8_v2.0-spapr-cpu-core,help qemu-system-ppc64: ../../hw/core/machine.c:1290: qdev_get_machine: Assertion `machine != NULL' failed. Aborted (core dumped) This used to work before QEMU 5.0, but commit 3df261b6676b unwillingly introduced a subtle regression : the above command line needs to create an instance but the instance_init function of the base class calls qdev_get_machine() before qemu_create_machine() has been called, which is a programming bug. Use current_machine instead. It is okay to skip the setting of nr_thread in this case since only its type is displayed. Fixes: 3df261b6676b ("softmmu/vl.c: Handle '-cpu help' and '-device help' before 'no default machine'") Reported-by: Thomas Huth Signed-off-by: Greg Kurz Cc: peter.maydell@linaro.org Message-Id: <20210409160339.500167-3-groug@kaod.org> Signed-off-by: Eduardo Habkost --- hw/cpu/core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/hw/cpu/core.c b/hw/cpu/core.c index 92d3b2fbad6..98760751557 100644 --- a/hw/cpu/core.c +++ b/hw/cpu/core.c @@ -66,10 +66,16 @@ static void core_prop_set_nr_threads(Object *obj, Visitor *v, const char *name, static void cpu_core_instance_init(Object *obj) { - MachineState *ms = MACHINE(qdev_get_machine()); CPUCore *core = CPU_CORE(obj); - core->nr_threads = ms->smp.threads; + /* + * Only '-device something-cpu-core,help' can get us there before + * the machine has been created. We don't care to set nr_threads + * in this case since it isn't used afterwards. + */ + if (current_machine) { + core->nr_threads = current_machine->smp.threads; + } } static void cpu_core_class_init(ObjectClass *oc, void *data)