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 3C454ECAAD3 for ; Wed, 7 Sep 2022 09:40:53 +0000 (UTC) Received: from localhost ([::1]:41252 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oVrYC-0003MO-7R for qemu-devel@archiver.kernel.org; Wed, 07 Sep 2022 05:40:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52360) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVrUV-000090-Hh for qemu-devel@nongnu.org; Wed, 07 Sep 2022 05:37:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:45677) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVrUT-0002EV-0L for qemu-devel@nongnu.org; Wed, 07 Sep 2022 05:37:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662543420; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lQCPRTP7XUHSgBJ+Q9RZr9/QFsEyL4XAXMORXHvWHUM=; b=Ihlr7ji/7QXxW47Jn5/dTw3yYu+nAuonQWlO8RGHKao8czTeF1ebxtYKRuQPrT93QtIgn2 4WQdWXLRYykEQwItMk9AFhBQmGPJ/Lsi6fcgjGg5SmRdWEQKEzrilANju/zpcWpWxp6+bx y+AOaysMdDXHAORKlOUSQQPzeuH6sds= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-403-AK4USgAaPXGgfBVa7PUVog-1; Wed, 07 Sep 2022 05:36:57 -0400 X-MC-Unique: AK4USgAaPXGgfBVa7PUVog-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8D9EC811E80; Wed, 7 Sep 2022 09:36:56 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.195.70]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 49B69492C3B; Wed, 7 Sep 2022 09:36:56 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 7796B180039B; Wed, 7 Sep 2022 11:36:54 +0200 (CEST) Date: Wed, 7 Sep 2022 11:36:54 +0200 From: Gerd Hoffmann To: Igor Mammedov Cc: Shameer Kolothum , qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, lersek@redhat.com, linuxarm@huawei.com, chenxiang66@hisilicon.com Subject: Re: [PATCH] fw_cfg: Don't set callback_opaque NULL in fw_cfg_modify_bytes_read() Message-ID: <20220907093654.3led26of3pqohjkc@sirius.home.kraxel.org> References: <20220825161842.841-1-shameerali.kolothum.thodi@huawei.com> <20220907105220.3f54efb3@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220907105220.3f54efb3@redhat.com> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-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" > > QEMU_EFI reports the below error: > > ProcessCmdAddPointer: invalid pointer value in "etc/acpi/tables" > > OnRootBridgesConnected: InstallAcpiTables: Protocol Error > > > > Debugging shows that on first reboot(after hot-adding NVDIMM), > > Qemu updates the etc/table-loader len, > > > > qemu_ram_resize() > >   fw_cfg_modify_file() > >      fw_cfg_modify_bytes_read() > > > > And in fw_cfg_modify_bytes_read() we set the "callback_opaque" for > > the "key" entry to NULL. Because of this, on the second reboot, > > virt_acpi_build_update() is called with a NULL "build_state" and > > returns without updating the ACPI tables. This seems to be > > upsetting the firmware. > > > > To fix this, don't change the callback_opaque in fw_cfg_modify_bytes_read(). > > Fixes: bdbb5b1706d165 ("fw_cfg: add fw_cfg_machine_reset function") > Acked-by: Igor Mammedov > > CCing Gerd to have a second set of eyes on it Hmm. Original patch clears both 'callback_opaque' and 'callback' (where 'callback' used to be what 'select_cb' is today I think). Not fully sure what the motivation was for that. Maybe because using both fw_cfg_modify*() calls and a callback for update-on-read for a given entry looks pointless. Should that be the case there are better ways to catch that, like having fw_cfg_modify_bytes_read() throw an error in case select_cb is not NULL instead of silently clearing the callback. In any case clearing callback_opaque only is obviously wrong, so Acked-by: Gerd Hoffmann take care, Gerd