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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id E6540C4707B for ; Thu, 11 Jan 2024 10:48:27 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.666145.1036633 (Exim 4.92) (envelope-from ) id 1rNsbj-0005Wb-42; Thu, 11 Jan 2024 10:48:19 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 666145.1036633; Thu, 11 Jan 2024 10:48:19 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rNsbj-0005WU-1A; Thu, 11 Jan 2024 10:48:19 +0000 Received: by outflank-mailman (input) for mailman id 666145; Thu, 11 Jan 2024 10:48:17 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rNsbh-0005WO-Qb for xen-devel@lists.xenproject.org; Thu, 11 Jan 2024 10:48:17 +0000 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id e49a174c-b06e-11ee-9b0f-b553b5be7939; Thu, 11 Jan 2024 11:48:03 +0100 (CET) Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2b-m6i4x-a893d89c.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2024 10:47:55 +0000 Received: from smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev (pdx2-ws-svc-p26-lb5-vlan2.pdx.amazon.com [10.39.38.66]) by email-inbound-relay-pdx-2b-m6i4x-a893d89c.us-west-2.amazon.com (Postfix) with ESMTPS id 4583D41092; Thu, 11 Jan 2024 10:47:54 +0000 (UTC) Received: from EX19MTAEUB001.ant.amazon.com [10.0.43.254:62621] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.47.189:2525] with esmtp (Farcaster) id 6501f36b-f066-4c5d-a5f5-94238a3f5c59; Thu, 11 Jan 2024 10:47:53 +0000 (UTC) Received: from EX19D018EUA002.ant.amazon.com (10.252.50.146) by EX19MTAEUB001.ant.amazon.com (10.252.51.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Thu, 11 Jan 2024 10:47:53 +0000 Received: from [10.95.99.82] (10.95.99.82) by EX19D018EUA002.ant.amazon.com (10.252.50.146) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Thu, 11 Jan 2024 10:47:49 +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 Sender: "Xen-devel" X-Inumbo-ID: e49a174c-b06e-11ee-9b0f-b553b5be7939 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1704970084; x=1736506084; h=message-id:date:mime-version:from:subject:to:cc: references:in-reply-to:content-transfer-encoding; bh=CfwwQc2KmGR36m1dd3AfRZExsPllzd43VXGN7zgsSqg=; b=sgd6WUp3n/Vdp7MxjZtbnPTFHsywGqw0GzUpGbWKli8OV9X5bDe2QIhE k5UuCepgTfWomrth4J6NMw+34SyLWCMIZ20gnMtMSg+w1cLfC0Wt+767F MJ0q32dES+Y31fO2e9GPk/yZEOU1Gmf0XvQUHHcTzYnp7b1y2Jrl8uEW5 A=; X-IronPort-AV: E=Sophos;i="6.04,185,1695686400"; d="scan'208";a="389113682" X-Farcaster-Flow-ID: 6501f36b-f066-4c5d-a5f5-94238a3f5c59 Message-ID: Date: Thu, 11 Jan 2024 10:47:45 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Elias El Yandouzi Subject: Re: [PATCH 11/22] x86: add a boot option to enable and disable the direct map To: Jan Beulich , Julien Grall CC: Hongyan Xia , Andrew Cooper , George Dunlap , Stefano Stabellini , Wei Liu , "Bertrand Marquis" , Volodymyr Babchuk , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Julien Grall , References: <20221216114853.8227-1-julien@xen.org> <20221216114853.8227-12-julien@xen.org> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.95.99.82] X-ClientProxiedBy: EX19D032UWA004.ant.amazon.com (10.13.139.56) To EX19D018EUA002.ant.amazon.com (10.252.50.146) Precedence: Bulk Hi, On 22/12/2022 13:24, Jan Beulich wrote: > That said, I think this change comes too early in the series, or there is > something missing. At first, I had the same feeling but looking at the rest of the series, I can see that the option is needed in follow-up patches. > As said in reply to patch 10, while there the mapcache > is being initialized for the idle domain, I don't think it can be used > just yet. Read through mapcache_current_vcpu() to understand why I think > that way, paying particular attention to the ASSERT() near the end. Would be able to elaborate a bit more why you think that? I haven't been able to get your point. > In preparation of this patch here I think the mfn_to_virt() uses have to all > disappear from map_domain_page(). Perhaps yet more strongly all > ..._to_virt() (except fix_to_virt() and friends) and __va() have to > disappear up front from x86 and any code path which can be taken on x86 > (which may simply mean purging all respective x86 #define-s, without > breaking the build in any way). I agree with you on that one. I think it is what we're aiming for in the long term. However, as mentioned by Julien in the cover letter, the series's name is a misnomer and I am afraid we won't be able to remove all of them with this series. These helpers would still be used for xenheap pages or when the direct map is enabled. -- Elias