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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 9AA91C04AB3 for ; Tue, 28 May 2019 01:37:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6F32A2081C for ; Tue, 28 May 2019 01:37:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F32A2081C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:55522 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVR3C-0007qG-Jo for qemu-devel@archiver.kernel.org; Mon, 27 May 2019 21:37:14 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50973) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVR2N-0007Y4-98 for qemu-devel@nongnu.org; Mon, 27 May 2019 21:36:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hVR2L-0001Hu-Mr for qemu-devel@nongnu.org; Mon, 27 May 2019 21:36:23 -0400 Received: from mga07.intel.com ([134.134.136.100]:5782) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hVR2L-0001G3-Fx for qemu-devel@nongnu.org; Mon, 27 May 2019 21:36:21 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 May 2019 18:36:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,520,1549958400"; d="scan'208";a="179049679" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga002.fm.intel.com with ESMTP; 27 May 2019 18:36:17 -0700 Date: Tue, 28 May 2019 09:35:48 +0800 From: Wei Yang To: Igor Mammedov Message-ID: <20190528013548.GA8813@richard> References: <20190411071739.22889-1-richardw.yang@linux.intel.com> <20190527142114.521ab953@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190527142114.521ab953@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.100 Subject: Re: [Qemu-devel] [PATCH] hw/i386/pc: check apci hotplug capability before nvdimm's X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Cc: thuth@redhat.com, ehabkost@redhat.com, qemu-devel@nongnu.org, Wei Yang , pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, May 27, 2019 at 02:21:14PM +0200, Igor Mammedov wrote: >On Thu, 11 Apr 2019 15:17:39 +0800 >Wei Yang wrote: > >> pc_memory_pre_plug() is called during hotplug for both pc-dimm and >> nvdimm. This is more proper to check apci hotplug capability before >> check nvdimm specific capability. >not sure what this about. >Currently we are checking if ACPI is enabled > if (!pcms->acpi_dev || !acpi_enabled) { ... >before nvdimm check and it looks better to me that we cancel >nvdimm hotplug earlier than passing it to > hotplug_handler_pre_plug(pcms->acpi_dev, dev, &local_err) >with this patch ACPI device handler will be called before >nvdimm check happens, so it's +1 unnecessary call chain in >the case of nvdimm, which I'd rather not have. > >Are there any issues with current call flow? >(commit message doesn't really explaining why we need this patch) > My idea is to check more generic requirement and then specific one. For example, the call flow looks like this: pc_memory_pre_plug piix4_device_pre_plug_cb | ich9_pm_device_pre_plug_cb if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) && !lpc->pm.acpi_memory_hotplug.is_enabled) if (is_nvdimm && !ms->nvdimms_state->is_enabled) In hotplug_handler_pre_plug(), it checks the acpi hotplug capability. And then if it has memory hotplug capability and is nvdimm, we check whether nvdimm is enabled. This is why I suggest to change the order here. No functional issue for current code. -- Wei Yang Help you, Help me