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 AFC73FCB607 for ; Fri, 6 Mar 2026 15:15:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vyWti-0006Zm-A5; Fri, 06 Mar 2026 10:15:26 -0500 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 1vyWtd-0006Y4-V4 for qemu-devel@nongnu.org; Fri, 06 Mar 2026 10:15:22 -0500 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 1vyWtc-00069P-Gz for qemu-devel@nongnu.org; Fri, 06 Mar 2026 10:15:21 -0500 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fS91W4wM5zJ46ZP; Fri, 6 Mar 2026 23:14:39 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id D60FB4056B; Fri, 6 Mar 2026 23:15:17 +0800 (CST) Received: from localhost (10.48.149.21) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 6 Mar 2026 15:15:16 +0000 Date: Fri, 6 Mar 2026 15:15:15 +0000 To: Alireza Sanaee CC: , , , , , , , , , , , , , , Subject: Re: [PATCH v7 3/3] hw/cxl: Add a performant (and correct) path for the non interleaved cases Message-ID: <20260306151515.000047a1@huawei.com> In-Reply-To: <20260306121151.883-4-alireza.sanaee@huawei.com> References: <20260306121151.883-1-alireza.sanaee@huawei.com> <20260306121151.883-4-alireza.sanaee@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.48.149.21] X-ClientProxiedBy: lhrpeml100012.china.huawei.com (7.191.174.184) To dubpeml500005.china.huawei.com (7.214.145.207) Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.411, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.679, 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: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Jonathan Cameron From: Jonathan Cameron via qemu development Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, 6 Mar 2026 12:11:51 +0000 Alireza Sanaee wrote: > The CXL address to device decoding logic is complex because of the need to > correctly decode fine grained interleave. The current implementation > prevents use with KVM where executed instructions may reside in that memory > and gives very slow performance even in TCG. > > In many real cases non interleaved memory configurations are useful and for > those we can use a more conventional memory region alias allowing similar > performance to other memory in the system. > > Whether this fast path is applicable can be established once the full set > of HDM decoders has been committed (in whatever order the guest decides to > commit them). As such a check is performed on each commit/uncommit of HDM > decoder to establish if the alias should be added or removed. > > Reviewed-by: Li Zhijian > Co-developed-by: Jonathan Cameron > Signed-off-by: Jonathan Cameron Changes look good to me. Thanks for the quick turn around. Jonathan > Signed-off-by: Alireza Sanaee