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 X-Spam-Level: X-Spam-Status: No, score=-15.1 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,USER_AGENT_SANE_1 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 A692FC07E9B for ; Wed, 21 Jul 2021 09:36:51 +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 441FD6023F for ; Wed, 21 Jul 2021 09:36:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 441FD6023F 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]:49328 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m68eo-00066v-FD for qemu-devel@archiver.kernel.org; Wed, 21 Jul 2021 05:36:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42838) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m68dA-0003Ua-Vo for qemu-devel@nongnu.org; Wed, 21 Jul 2021 05:35:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:22354) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m68d9-0006k7-1g for qemu-devel@nongnu.org; Wed, 21 Jul 2021 05:35:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626860106; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=O9w+gfWxwCvj24rlWnzalgbrbAKDAF+wPKNb+lLC+kk=; b=G6AE4Ge9sgyQncXrQ+QsNg6CcdgVpmao7MdCkDhtHcBE5IdzfrvlUS9xPS3J4kB3g9aO7D 0xj6Etgf60lF+G/w13Op5cZwBg5nY6YbcGpdG8qLd0cwYacmYkSi1RVH6vgMcEHq5vte67 6UHkXPB5ZYzd/jcvBKKfc/1Mn029LnY= 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-572-gSsBP4R0PsCZsaYP_OAPEQ-1; Wed, 21 Jul 2021 05:34:57 -0400 X-MC-Unique: gSsBP4R0PsCZsaYP_OAPEQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E6D98802E29; Wed, 21 Jul 2021 09:34:56 +0000 (UTC) Received: from redhat.com (ovpn-114-135.ams2.redhat.com [10.36.114.135]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6BB7160583; Wed, 21 Jul 2021 09:34:51 +0000 (UTC) Date: Wed, 21 Jul 2021 10:34:48 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Jose R. Ziviani" Subject: Re: [PATCH 2/2] qom: Improve error message in module_object_class_by_name() Message-ID: References: <20210720223120.21711-1-jziviani@suse.de> <20210720223120.21711-3-jziviani@suse.de> MIME-Version: 1.0 In-Reply-To: <20210720223120.21711-3-jziviani@suse.de> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.474, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: ehabkost@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org, cfontana@suse.de, pbonzini@redhat.com, kraxel@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jul 20, 2021 at 07:31:20PM -0300, Jose R. Ziviani wrote: > module_object_class_by_name() calls module_load_qom_one if the object > is provided by a dynamically linked library. Such library might not be > available at this moment - for instance, it can be a package not yet > installed. Thus, instead of assert error messages, this patch outputs > more friendly messages. > > Current error messages: > $ ./qemu-system-x86_64 -machine q35 -accel tcg -kernel /boot/vmlinuz > ... > ERROR:../accel/accel-softmmu.c:82:accel_init_ops_interfaces: assertion failed: (ops != NULL) > Bail out! ERROR:../accel/accel-softmmu.c:82:accel_init_ops_interfaces: assertion failed: (ops != NULL) > [1] 31964 IOT instruction (core dumped) ./qemu-system-x86_64 ... > > New error message: > $ ./qemu-system-x86_64 -machine q35 -accel tcg -kernel /boot/vmlinuz > accel-tcg-x86_64 module is missing, install the package or config the library path correctly. > > Or with other modules, when possible: > $ ./qemu-system-x86_64 -machine q35 -accel kvm -kernel /boot/vmlinuz -vga qxl ✹ > hw-display-qxl module is missing, install the package or config the library path correctly. > qemu-system-x86_64: QXL VGA not available > > $ make check > ... > Running test qtest-x86_64/test-filter-mirror > Running test qtest-x86_64/endianness-test > accel-qtest-x86_64 module is missing, install the package or config the library path correctly. > accel-qtest-x86_64 module is missing, install the package or config the library path correctly. > accel-qtest-x86_64 module is missing, install the package or config the library path correctly. > accel-qtest-x86_64 module is missing, install the package or config the library path correctly. > accel-qtest-x86_64 module is missing, install the package or config the library path correctly. > accel-tcg-x86_64 module is missing, install the package or config the library path correctly. > ... > > Signed-off-by: Jose R. Ziviani > --- > accel/accel-softmmu.c | 5 ++++- > qom/object.c | 9 +++++++++ > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/accel/accel-softmmu.c b/accel/accel-softmmu.c > index 67276e4f52..52449ac2d0 100644 > --- a/accel/accel-softmmu.c > +++ b/accel/accel-softmmu.c > @@ -79,7 +79,10 @@ void accel_init_ops_interfaces(AccelClass *ac) > * all accelerators need to define ops, providing at least a mandatory > * non-NULL create_vcpu_thread operation. > */ > - g_assert(ops != NULL); > + if (ops == NULL) { > + exit(1); > + } > + > if (ops->ops_init) { > ops->ops_init(ops); > } > diff --git a/qom/object.c b/qom/object.c > index 6a01d56546..3a170ea9df 100644 > --- a/qom/object.c > +++ b/qom/object.c > @@ -10,6 +10,7 @@ > * See the COPYING file in the top-level directory. > */ > > +#include "qemu/module.h" > #include "qemu/osdep.h" > #include "hw/qdev-core.h" > #include "qapi/error.h" > @@ -1031,8 +1032,16 @@ ObjectClass *module_object_class_by_name(const char *typename) > oc = object_class_by_name(typename); > #ifdef CONFIG_MODULES > if (!oc) { > + const char *module_name = module_get_name_from_obj(typename); > module_load_qom_one(typename); > oc = object_class_by_name(typename); > + if (!oc && module_name) { > + if (!module_is_loaded(module_name)) { > + fprintf(stderr, "%s module is missing, install the " > + "package or config the library path " > + "correctly.\n", module_name); > + } > + } > } Introducing a call to module_is_loaded is feels like it isn't really addressing the root cause. The error scenario here exists because module_load_qom_one() can fail to load the requested module. We don't detect that failure because module_load_qom_one() is "void" for some reason. There are several possible causes of failure and missing file on disk is only one of them. This general error message about "module_name" being missing is misleading when there are dependancies involved. "module_name" may well exist, but something it depends on might be missing. Or the modules might have been built from wrong QEMU and be unable to be dlopened despite existing. I think we need to fix module_load_qom_one() so that it can actually report failure via an "Error **errp" parameter. This will also entail fixing a number of methods it in turn calls. 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 :|