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 A191BCAC5B8 for ; Tue, 30 Sep 2025 08:24:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v3Vdc-0000ET-4c; Tue, 30 Sep 2025 04:23:08 -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 1v3VdG-0008W9-I0 for qemu-devel@nongnu.org; Tue, 30 Sep 2025 04:22:47 -0400 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 1v3VcU-0000oc-VP for qemu-devel@nongnu.org; Tue, 30 Sep 2025 04:22:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1759220511; 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: in-reply-to:in-reply-to:references:references; bh=fOgK8Rj4RLSl64NdTyDOu6qpfuXmT4oW+TX2rEPOAHg=; b=jTUrmWrRdcQ45e+FLSuGE0OwKlXnofQiRhVyC3GtqqTulgGN3GBOKgeitDZqdpm3sxsOdl gwPKjsxkZk1aIwmSG+NhIj4naET26E9qsSkh20HfW9B4m50cXTpdaa3mGqnF6D74HP99cs 16xHhAoFOZbYxVFJdSdt9v8Jvo4VvkM= 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-616-AuvH5StMP5CK-EiyK6UNKg-1; Tue, 30 Sep 2025 04:21:47 -0400 X-MC-Unique: AuvH5StMP5CK-EiyK6UNKg-1 X-Mimecast-MFC-AGG-ID: AuvH5StMP5CK-EiyK6UNKg_1759220506 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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 28E2A19560AB; Tue, 30 Sep 2025 08:21:46 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.14]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DE20419560B4; Tue, 30 Sep 2025 08:21:44 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5990F21E6A27; Tue, 30 Sep 2025 10:21:42 +0200 (CEST) From: Markus Armbruster To: Vladimir Sementsov-Ogievskiy Cc: qemu-devel@nongnu.org, odaki@rsg.ci.i.u-tokyo.ac.jp, marcandre.lureau@redhat.com, berrange@redhat.com, richard.henderson@linaro.org, Jagannathan Raman Subject: Re: [PATCH v3 05/13] hw/remote/vfio-user: Clean up error reporting In-Reply-To: <77f8b8ba-911e-4965-bb10-2c0cc31a0d3d@yandex-team.ru> (Vladimir Sementsov-Ogievskiy's message of "Tue, 30 Sep 2025 11:02:38 +0300") References: <20250923091000.3180122-1-armbru@redhat.com> <20250923091000.3180122-6-armbru@redhat.com> <1a10e0d3-17fc-4ec9-aa4c-cdfed13988e6@yandex-team.ru> <878qi1so4j.fsf@pond.sub.org> <77f8b8ba-911e-4965-bb10-2c0cc31a0d3d@yandex-team.ru> Date: Tue, 30 Sep 2025 10:21:42 +0200 Message-ID: <87a52cz6y1.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@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=-0.513, 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_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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Vladimir Sementsov-Ogievskiy writes: > On 26.09.25 09:51, Markus Armbruster wrote: >> Vladimir Sementsov-Ogievskiy writes: >> >>> On 23.09.25 12:09, Markus Armbruster wrote: >>>> VFU_OBJECT_ERROR() reports the error with error_setg(&error_abort, >>>> ...) when auto-shutdown is enabled, else with error_report(). >>>> >>>> Issues: >>>> >>>> 1. The error is serious enough to warrant aborting the process when >>>> auto-shutdown is enabled, yet harmless enough to permit carrying on >>>> when it's disabled. This makes no sense to me. >>>> >>>> 2. Like assert(), &error_abort is strictly for programming errors. Is >>>> this one? >>> >>> Brief look at the code make me think that, no it isn't. >> So the use of &error_abort is wrong. >> >>>> Or should we exit(1) instead? >>>> >>>> 3. qapi/error.h advises "don't error_setg(&error_abort, ...), use >>>> assert()." >>>> >>>> This patch addresses just 3. >>>> >>>> Cc: Jagannathan Raman >>>> Signed-off-by: Markus Armbruster >>>> --- >>>> hw/remote/vfio-user-obj.c | 9 +++------ >>>> 1 file changed, 3 insertions(+), 6 deletions(-) >>>> diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c >>>> index ea6165ebdc..eb96982a3a 100644 >>>> --- a/hw/remote/vfio-user-obj.c >>>> +++ b/hw/remote/vfio-user-obj.c >>>> @@ -75,12 +75,9 @@ OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT) >>>> */ >>>> #define VFU_OBJECT_ERROR(o, fmt, ...) \ >>>> { \ >>>> - if (vfu_object_auto_shutdown()) { \ >>>> - error_setg(&error_abort, (fmt), ## __VA_ARGS__); \ >>>> - } else { \ >>>> - error_report((fmt), ## __VA_ARGS__); \ >>>> - } \ >>>> - } \ >>>> + error_report((fmt), ## __VA_ARGS__); \ >>>> + assert(!vfu_object_auto_shutdown()); \ >>> >>> Probably, it's only my feeling, but for me, assert() is really strictly bound >>> to programming errors, more than abort(). Using abort() for errors which are >>> not programming, but we can't handle them looks less confusing, i.e. >>> >>> if (vfu_object_auto_shutdown()) { >>> abort(); >>> } >> >> assert(COND) is if (COND) abort() plus a message meant to help >> developers. Both are for programming errors. If it isn't something >> that needs debugging, why dump core? >> >> But this particular error condition is *not* a programming error. So >> assert(!vfu_object_auto_shutdown()); >> >> and >> >> if (vfu_object_auto_shutdown()) { >> abort(); >> } >> >> are both equally wrong. However, the latter makes it easier to add a >> FIXME comment: >> >> if (vfu_object_auto_shutdown()) { >> /* >> * FIXME This looks inappropriate. The error is serious >> * enough programming error to warrant aborting the process >> * when auto-shutdown is enabled, yet harmless enough to >> * permit carrying on when it's disabled. Makes no sense. >> */ >> abort(); >> } >> > > Looks more readable, yes. Sold! >> The commit message would then need a tweak. Perhaps >> >> Issues: >> >> 1. The error is serious enough to warrant killing the process when >> auto-shutdown is enabled, yet harmless enough to permit carrying on >> when it's disabled. This makes no sense to me. >> >> 2. Like assert(), &error_abort is strictly for programming errors. Is >> this one? Vladimir Sementsov-Ogievskiy tells me it's not. > > :)) I'm not an expert in vfio-user at all. But yes, I said it:) I'll soften it to "believes it's not." >> 3. qapi/error.h advises "don't error_setg(&error_abort, ...), use >> assert()." >> >> This patch addresses just 3. It adds a FIXME comment for the other >> two. >> >> Thoughts? > > Looks good. Thanks again! >> >>> Not really matter. Anyway: >>> >>> Reviewed-by: Vladimir Sementsov-Ogievskiy >> Thanks! >> >>>> + } >>>> struct VfuObjectClass { >>>> ObjectClass parent_class; >>