From patchwork Fri Jan 17 19:21:06 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 13943937 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 9DDB5C02183 for ; Fri, 17 Jan 2025 19:21:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tYruE-0002UN-Lc; Fri, 17 Jan 2025 14:21:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tYruC-0002UA-5m for qemu-devel@nongnu.org; Fri, 17 Jan 2025 14:21:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tYruA-0008BY-Ez for qemu-devel@nongnu.org; Fri, 17 Jan 2025 14:21:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737141677; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=aCpLVc9AMKm7QfyYqSU8fXrC2KisDrJRpA7sf4qSdCw=; b=c+Cw0DJJ7v1nDZQJ1ZNDYXOXbWNT7N8O9yNKCyYyG2rV4oGKdFMf8d3oZm9c49gkhbeSTb JA+mB1QLuwQVy1iYffSKZH1BRruXCocYrvxy40HEnl8gylNSG9HcZ1g8EPlorP5fGCS663 exixjpRfW718UY/FVBy6R3mj+DQzab8= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-571-T0aMoKWOM8KL1KlLRrH0eg-1; Fri, 17 Jan 2025 14:21:11 -0500 X-MC-Unique: T0aMoKWOM8KL1KlLRrH0eg-1 X-Mimecast-MFC-AGG-ID: T0aMoKWOM8KL1KlLRrH0eg Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 89FE5196A961; Fri, 17 Jan 2025 19:21:10 +0000 (UTC) Received: from thuth-p1g4.redhat.com (unknown [10.39.192.47]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id EBC0B19560AE; Fri, 17 Jan 2025 19:21:07 +0000 (UTC) From: Thomas Huth To: qemu-devel@nongnu.org, Paolo Bonzini , "Michael S. Tsirkin" , Marcel Apfelbaum Cc: Richard Henderson , Eduardo Habkost Subject: [PATCH] hw/i386/pc: Fix crash that occurs when introspecting TYPE_PC_MACHINE machines Date: Fri, 17 Jan 2025 20:21:06 +0100 Message-ID: <20250117192106.471029-1-thuth@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.129.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.132, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org QEMU currently crashes when you try to inspect the machines based on TYPE_PC_MACHINE for their properties: $ echo '{ "execute": "qmp_capabilities" } { "execute": "qom-list-properties","arguments": { "typename": "pc-q35-10.0-machine"}}' \ | ./qemu-system-x86_64 -M pc -qmp stdio {"QMP": {"version": {"qemu": {"micro": 50, "minor": 2, "major": 9}, "package": "v9.2.0-1070-g87e115c122-dirty"}, "capabilities": ["oob"]}} {"return": {}} Segmentation fault (core dumped) This happens because TYPE_PC_MACHINE machines add a machine_init- done_notifier in their instance_init function - but instance_init of machines are not only called for machines that are realized, but also for machines that are introspected, so in this case the listener is added for a q35 machine that is never realized. But since there is already a running pc machine, the listener function is triggered immediately, causing a crash since it was not for the right machine it was meant for. Such listener functions must never be installed from an instance_init function. Let's do it from pc_basic_device_init() instead - this function is called from the MachineClass->init() function instead, i.e. guaranteed to be only called once in the lifetime of a QEMU process. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2779 Signed-off-by: Thomas Huth --- hw/i386/pc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index b46975c8a4..85b8a76455 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1241,6 +1241,9 @@ void pc_basic_device_init(struct PCMachineState *pcms, /* Super I/O */ pc_superio_init(isa_bus, create_fdctrl, pcms->i8042_enabled, pcms->vmport != ON_OFF_AUTO_ON, &error_fatal); + + pcms->machine_done.notify = pc_machine_done; + qemu_add_machine_init_done_notifier(&pcms->machine_done); } void pc_nic_init(PCMachineClass *pcmc, ISABus *isa_bus, PCIBus *pci_bus) @@ -1714,9 +1717,6 @@ static void pc_machine_initfn(Object *obj) if (pcmc->pci_enabled) { cxl_machine_init(obj, &pcms->cxl_devices_state); } - - pcms->machine_done.notify = pc_machine_done; - qemu_add_machine_init_done_notifier(&pcms->machine_done); } static void pc_machine_reset(MachineState *machine, ResetType type)