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=-7.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 D3241C433ED for ; Wed, 28 Apr 2021 10:14:45 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 935BC613C8 for ; Wed, 28 Apr 2021 10:14:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 935BC613C8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.119184.225573 (Exim 4.92) (envelope-from ) id 1lbhDC-0005w3-0e; Wed, 28 Apr 2021 10:14:30 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 119184.225573; Wed, 28 Apr 2021 10:14:29 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbhDB-0005vw-TU; Wed, 28 Apr 2021 10:14:29 +0000 Received: by outflank-mailman (input) for mailman id 119184; Wed, 28 Apr 2021 10:14:29 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbhDA-0005vr-TE for xen-devel@lists.xenproject.org; Wed, 28 Apr 2021 10:14:29 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lbhD8-0002qo-IG; Wed, 28 Apr 2021 10:14:26 +0000 Received: from 54-240-197-239.amazon.com ([54.240.197.239] helo=ua82172827c7b5a.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lbhD8-0006hL-2G; Wed, 28 Apr 2021 10:14:26 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Mime-Version:Content-Type: References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID; bh=WwQ0JBul44XZzb6di5GoXeN52HnDI99XCMYHc3FiYss=; b=EQZy+fxzmejz2bJMAQevBPOLpV 6eCKiiehHnInTM+wjfgKkozQkAwxn8YECMrbABq6YzOjAr+uAip/YzuJkLn1tOAW93U6LiJLc1oBA rgFSPV+Z1dvrJCdL4PUWfo7P0+Fsf2wfStOf/S9/iVuuq/PYHUVmsmRmcVf9k5l++z5s=; Message-ID: <5562d4e4df8a6efc4f74486d24a85339c9803b6f.camel@xen.org> Subject: Re: [PATCH 00/16] Remove the direct map From: Hongyan Xia To: Wei Liu Cc: Stefano Stabellini , julien@xen.org, Andrew Cooper , Ian Jackson , George Dunlap , Jan Beulich , xen-devel@lists.xenproject.org, Volodymyr Babchuk , Roger Pau =?ISO-8859-1?Q?Monn=E9?= Date: Wed, 28 Apr 2021 11:14:21 +0100 In-Reply-To: <20200602090851.hxfxwoiflip6kcym@liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net> References: <20200501120715.hjak2gjp7ialwfq5@liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net> <689a7c860a8a551e3b6009b16590e812dbf21055.camel@xen.org> <20200602090851.hxfxwoiflip6kcym@liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit On Tue, 2020-06-02 at 09:08 +0000, Wei Liu wrote: > On Fri, May 01, 2020 at 02:53:08PM +0100, Hongyan Xia wrote: [...] > Not sure about hiding EPT. I will leave this question to Jan and > Andrew... Quick update on performance numbers. I have seen noticeable performance drop if we need to map and unmap EPT. This translates to up to 10% degredation in networking and database applications. With EPT always mapped (not considering it as secrets), I have not seen any noticeable performance drop in any real-world applications. The only performance drop is from a micro-benchmark that programs HPET in a tight loop (abusing MMIO page table walks), and the worst case is around 10% to 15%. Note that all above results are based on the mapcache rewrite patch 4058e92ce21627731c49b588a95809dc0affd83a.1581015491.git.hongyxia@amazon.com to fix the mapcache lock contention first. Hongyan