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 048B8EB64D9 for ; Mon, 3 Jul 2023 01:34:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qG8S9-00082m-Te; Sun, 02 Jul 2023 21:34:10 -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 1qG8S5-00082a-DC for qemu-devel@nongnu.org; Sun, 02 Jul 2023 21:34:06 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qG8S2-0006Mt-FR for qemu-devel@nongnu.org; Sun, 02 Jul 2023 21:34:04 -0400 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4QvSzw3S8yz688Z4; Mon, 3 Jul 2023 09:30:52 +0800 (CST) Received: from localhost (10.34.206.101) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 3 Jul 2023 02:33:43 +0100 Date: Mon, 3 Jul 2023 09:33:39 +0800 To: "nifan@outlook.com" CC: Fan Ni , "qemu-devel@nongnu.org" , "linux-cxl@vger.kernel.org" , "gregory.price@memverge.com" , "hchkuo@avery-design.com.tw" , "cbrowy@avery-design.com" , "ira.weiny@intel.com" , "dan.j.williams@intel.com" , Adam Manzanares , "dave@stgolabs.net" , "nmtadam.samsung@gmail.com" Subject: Re: [RFC 7/7] hw/mem/cxl_type3: add read/write support to dynamic capacity Message-ID: <20230703093339.00002fb2@Huawei.com> In-Reply-To: References: <20230511175609.2091136-1-fan.ni@samsung.com> <20230511175609.2091136-8-fan.ni@samsung.com> <20230515162212.0000275c@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.34.206.101] X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, 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: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 28 Jun 2023 10:09:47 -0700 "nifan@outlook.com" wrote: > The 05/15/2023 16:22, Jonathan Cameron wrote: > > On Thu, 11 May 2023 17:56:40 +0000 > > Fan Ni wrote: > > > > > From: Fan Ni > > > > > > Before the change, read from or write to dynamic capacity of the memory > > > device is not support as 1) no host backed file/memory is provided for > > > it; 2) no address space is created for the dynamic capacity. > > > > Ah nice. I should have read ahead. Probably makes sense to reorder things > > so that when we present DCD region it will work. > > We can back dynamic capacity with host memory/file and create address > space for dc regions, but until extents can be added we should not expect > any read/write can happen to the dynamic capacity, right? True. Seems logically 'unusual' though to set up the routing etc, but not plumb the actual memory access i until later. I guess it all comes together in the end and doing it this way lets you handle the extent mapping later. So fine to leave it as you have it. Jonathan