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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2A9EC77B7E for ; Tue, 30 May 2023 00:17:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229524AbjE3ARi (ORCPT ); Mon, 29 May 2023 20:17:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbjE3ARh (ORCPT ); Mon, 29 May 2023 20:17:37 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15F9ED9 for ; Mon, 29 May 2023 17:16:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685405809; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cBl3q2i812Jlu/HY8zePZKnZZJeg4miQ7XeIUUOuIUs=; b=EC8IjAlaEJeGBXv9msEe2PdkvOHjVXRikyqJlItGhZoe36YjqmxzdlK8Xusjb+bAPiqU1d Pd9R5CwwQwv14isZMokhEHJtOQjvrhAPxvS1sHuCbIeSEv2NQf3GNmqS4NICocYOWj0MWH gtau7H3FlWceDAlkbuGcACATVJVvFhI= Received: from mail-il1-f200.google.com (mail-il1-f200.google.com [209.85.166.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-317-SiEXZEtGMB2A_uegZ8il2g-1; Mon, 29 May 2023 20:16:47 -0400 X-MC-Unique: SiEXZEtGMB2A_uegZ8il2g-1 Received: by mail-il1-f200.google.com with SMTP id e9e14a558f8ab-33b4cbdd21aso22877895ab.2 for ; Mon, 29 May 2023 17:16:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685405807; x=1687997807; h=content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=cBl3q2i812Jlu/HY8zePZKnZZJeg4miQ7XeIUUOuIUs=; b=iq4A0lzODNdLBSsd2bB5G4FDYmhTBPjaNmnW4Hr9RiHWKGAPzbvQxFb9J0aD1S1m5p cJOCd/rT25B72PxgVK/2TvN+D4ouMxq5msiJANqlEZlrpA5+r8IY6CaqKEQooaYKpOxc aNp1Ivg8HSLNlgMAJlDXf4oMXB7bZs6wUAkAuHD4bIHAaxpxt4vQfVv4estQ031pD1/g NTk/0p8VLQ96Q4JiUzBcWMbr1S7Ibe7Zny7+Rm06g2G3vwLv/J+yRYd8/IFWAds0n6Pc II/FX6zwWPNSGZ97qxHgHq3fCEe1sPScNx7sVDcW+NwoA8m+/0mmUS9p0w8oqq4NzINL 7J5A== X-Gm-Message-State: AC+VfDzE+SYtLbChZhliod+L2GkkIhsuRnXkbgtrWrevb9ieQvhbm7ch yFpO2+Y2TVjYctBaM6doR+wQ/wWCJoOPwLExOGCGJDFgwSJOAXnEcqh0Re7yXsnMYev2dv3gIQv 4YHzZGNvh1Cp/v1qUCKm+WWZLvHT8 X-Received: by 2002:a92:dcc1:0:b0:328:8770:b9c2 with SMTP id b1-20020a92dcc1000000b003288770b9c2mr507362ilr.14.1685405807097; Mon, 29 May 2023 17:16:47 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ73yMhHh+AVUWd+tWnEm39ZtbwzqfO2AHakkj3n4fptb2pthTIWuj5Tj1tTy9hAry5+QAej4w== X-Received: by 2002:a92:dcc1:0:b0:328:8770:b9c2 with SMTP id b1-20020a92dcc1000000b003288770b9c2mr507347ilr.14.1685405806881; Mon, 29 May 2023 17:16:46 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id d6-20020a926806000000b003248469e5easm590655ilc.43.2023.05.29.17.16.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 May 2023 17:16:46 -0700 (PDT) Date: Mon, 29 May 2023 18:16:44 -0600 From: Alex Williamson To: Jason Gunthorpe Cc: "Tian, Kevin" , "Liu, Yi L" , "joro@8bytes.org" , "robin.murphy@arm.com" , "baolu.lu@linux.intel.com" , "cohuck@redhat.com" , "eric.auger@redhat.com" , "nicolinc@nvidia.com" , "kvm@vger.kernel.org" , "mjrosato@linux.ibm.com" , "chao.p.peng@linux.intel.com" , "yi.y.sun@linux.intel.com" , "peterx@redhat.com" , "jasowang@redhat.com" , "shameerali.kolothum.thodi@huawei.com" , "lulu@redhat.com" , "suravee.suthikulpanit@amd.com" , "iommu@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-kselftest@vger.kernel.org" , "Duan, Zhenzhong" Subject: Re: [PATCH v3 00/10] Add Intel VT-d nested translation Message-ID: <20230529181644.3a6a5c7b.alex.williamson@redhat.com> In-Reply-To: References: <20230511145110.27707-1-yi.l.liu@intel.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Mon, 29 May 2023 15:43:02 -0300 Jason Gunthorpe wrote: > On Wed, May 24, 2023 at 08:59:43AM +0000, Tian, Kevin wrote: > > > At least this looks a reasonable tradeoff to some proprietary VMMs > > which never adds RO mappings in stage-2 today. > > What is the reason for the RO anyhow? > > Would it be so bad if it was DMA mapped as RW due to the errata? What if it's the zero page? Thanks, Alex