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 C2973CAC5A7 for ; Mon, 22 Sep 2025 10:48:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v0e5b-0005s3-Gw; Mon, 22 Sep 2025 06:48:11 -0400 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 1v0e5Z-0005rc-5o for qemu-devel@nongnu.org; Mon, 22 Sep 2025 06:48:09 -0400 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 1v0e5T-0006fe-1b for qemu-devel@nongnu.org; Mon, 22 Sep 2025 06:48:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758538081; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=WORoLsoj0sPuQBAA6v1y9xG6PaRABbxQin0DlUaVmyE=; b=Xixf2RhaICvmaL1M2CwkcV34W4eVXyZQ2t2J6WmkKt4q1r1oAXDeHrTdn/u5I3wMPelpv/ IeEI8jqoHQ9QD9yBGNfsi81SrneHgVzyiYnMVuwlhEq6ESWGymxluiPPjaa/1/ovuq1cOl bD+nCRwPgspwLKUDBa+jfIDsCYquTm4= Received: from mx-prod-mc-02.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-317-GvSh-fMMN6-ZwEE2hzhwFg-1; Mon, 22 Sep 2025 06:47:57 -0400 X-MC-Unique: GvSh-fMMN6-ZwEE2hzhwFg-1 X-Mimecast-MFC-AGG-ID: GvSh-fMMN6-ZwEE2hzhwFg_1758538076 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A152A19560A0; Mon, 22 Sep 2025 10:47:56 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.69]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2EA7E1954128; Mon, 22 Sep 2025 10:47:53 +0000 (UTC) Date: Mon, 22 Sep 2025 11:47:50 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: Alessandro Ratti , alex.bennee@linaro.org, alessandro.ratti@gmail.com, philmd@linaro.org, qemu-devel@nongnu.org Subject: Re: [PATCH v2] virtio: Add function name to error messages Message-ID: References: <87a52wqa03.fsf@draig.linaro.org> <20250915162643.44716-1-alessandro@0x65c.net> <20250915162643.44716-2-alessandro@0x65c.net> <87h5wulqm2.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87h5wulqm2.fsf@pond.sub.org> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.442, 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_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_PASS=-0.001, T_SPF_HELO_TEMPERROR=0.01 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: , 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 Mon, Sep 22, 2025 at 12:37:57PM +0200, Markus Armbruster wrote: > Alessandro Ratti writes: > > > Replace virtio_error() with a macro that automatically prepends the > > calling function name to error messages. This provides better context > > for debugging virtio issues by showing exactly which function > > encountered the error. > > > > Before: "Invalid queue size: 1024" > > After: "virtio_queue_set_num: Invalid queue size: 1024" > > > > The implementation uses a macro to insert __func__ at compile time, > > avoiding any runtime overhead while providing more specific error > > context than a generic "virtio:" prefix. > > A need for function names and such in error messages suggests the error > messages are crap. I pretty much agree. If we take that view forwards, then I think our coding guidelines should explicitly state something like "Function names must never be included in error messages. The messages need to be sufficiently descriptive in their text, such that including function names is redundant" > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/230 This is interesting as it shows a link to a previously proposed patch: https://patchwork.kernel.org/project/qemu-devel/patch/20220414112902.41390-1-codeguy.moteen@gmail.com/ this old patch just expanded the error messages to include 'Virtio ' in their text. I'm not going to claim this made new error messages hugely user friendly, but I think that old patch approach was at least conceptually better & preferrable to the function name addition. > > Buglink: https://bugs.launchpad.net/qemu/+bug/1919021 > > > > Signed-off-by: Alessandro Ratti 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 :|