From mboxrd@z Thu Jan 1 00:00:00 1970 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 8AFE7CF34A1 for ; Wed, 19 Nov 2025 13:36:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vLiLs-0001QV-1B; Wed, 19 Nov 2025 08:36:04 -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 1vLiLl-0001P5-RN for qemu-devel@nongnu.org; Wed, 19 Nov 2025 08:35:58 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vLiLi-0000jH-VD for qemu-devel@nongnu.org; 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Wed, 19 Nov 2025 13:35:44 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.69]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 69E29180049F; Wed, 19 Nov 2025 13:35:35 +0000 (UTC) Date: Wed, 19 Nov 2025 13:35:32 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Andrew Cooper Cc: Markus Armbruster , qemu-devel@nongnu.org, kwolf@redhat.com, hreitz@redhat.com, mst@redhat.com, imammedo@redhat.com, anisinha@redhat.com, gengdongjiu1@gmail.com, peter.maydell@linaro.org, alistair@alistair23.me, edgar.iglesias@gmail.com, npiggin@gmail.com, harshpb@linux.ibm.com, palmer@dabbelt.com, liwei1518@gmail.com, dbarboza@ventanamicro.com, zhiwei_liu@linux.alibaba.com, sstabellini@kernel.org, anthony@xenproject.org, paul@xen.org, peterx@redhat.com, farosas@suse.de, eblake@redhat.com, vsementsov@yandex-team.ru, eduardo@habkost.net, marcel.apfelbaum@gmail.com, philmd@linaro.org, wangyanan55@huawei.com, zhao1.liu@intel.com, qemu-block@nongnu.org, qemu-arm@nongnu.org, qemu-ppc@nongnu.org, qemu-riscv@nongnu.org, xen-devel@lists.xenproject.org Subject: Re: [PATCH 5/5] error: Consistently name Error * objects err, and not errp Message-ID: References: <20251119130855.105479-1-armbru@redhat.com> <20251119130855.105479-6-armbru@redhat.com> <3ffe11b9-db81-4930-aefa-e55d758645bf@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <3ffe11b9-db81-4930-aefa-e55d758645bf@citrix.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Nov 19, 2025 at 01:22:06PM +0000, Andrew Cooper wrote: > On 19/11/2025 1:08 pm, Markus Armbruster wrote: > > diff --git a/hw/xen/xen-pvh-common.c b/hw/xen/xen-pvh-common.c > > index b93ff80c85..3e62ec09d0 100644 > > --- a/hw/xen/xen-pvh-common.c > > +++ b/hw/xen/xen-pvh-common.c > > @@ -101,7 +101,7 @@ static void xen_create_virtio_mmio_devices(XenPVHMachineState *s) > > #ifdef CONFIG_TPM > > static void xen_enable_tpm(XenPVHMachineState *s) > > { > > - Error *errp = NULL; > > + Error *err = NULL; > > DeviceState *dev; > > SysBusDevice *busdev; > > > > @@ -111,8 +111,15 @@ static void xen_enable_tpm(XenPVHMachineState *s) > > return; > > } > > dev = qdev_new(TYPE_TPM_TIS_SYSBUS); > > - object_property_set_link(OBJECT(dev), "tpmdev", OBJECT(be), &errp); > > - object_property_set_str(OBJECT(dev), "tpmdev", be->id, &errp); > > + /* > > + * FIXME This use of &err is is wrong. If both calls fail, the > > + * second will trip error_setv()'s assertion. If just one call > > + * fails, we leak an Error object. Setting the same property > > + * twice (first to a QOM path, then to an ID string) is almost > > + * certainly wrong, too. > > + */ > > + object_property_set_link(OBJECT(dev), "tpmdev", OBJECT(be), &err); > > + object_property_set_str(OBJECT(dev), "tpmdev", be->id, &err); > > To your question, I don't know the answer, but I think it's far more > likely that the original author didn't grok the proper use of &errp, > than for this behaviour to be intentional. > > Surely we just want a failure path and abort the construction if this > goes wrong? In the caller of xen_enable_tpm, we just have error_report+exit calls, so there's no error propagation ability in the call chain. The caller will also skip xen_enable_tpm unless a TPM was explicitly requested in the config. Given that, I'm inclined to say that the object_property_set_* calls in xen_enable_tpm should be using &error_abort, as a failure to setup the explicitly requested TPM should be fatal. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|