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=-1.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS autolearn=ham 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 0AEE5C43381 for ; Thu, 21 Feb 2019 11:56:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA78C20880 for ; Thu, 21 Feb 2019 11:56:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="GmHkWxAk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727551AbfBUL4p (ORCPT ); Thu, 21 Feb 2019 06:56:45 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:52420 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725820AbfBUL4p (ORCPT ); Thu, 21 Feb 2019 06:56:45 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x1LBsc0B035676; Thu, 21 Feb 2019 11:55:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=Pbq0pvPOHEEJ+KrRRgeyvszIi/z/+hzos7hFkkP1w74=; b=GmHkWxAk1iIPPv86Vvh3PdDb2Tl90iilKrF8nfs07s0exHy6e3hKUGI+Gomw1huQqbox CGrXa5AYkbjUoEJe/AomYIIYR4a4OAzvbbEidd19PGy5qoQbjC+87uXDPVp2/pjnD4PB MmnB3HJtVYv6F8yw9aLbViwTPP6guX32/UnljBCbqtBTOBpPTUNcGKrdfmeCcGYZBV6Q jZwuIXRdgfrXYyN2QdgBkC5niMPmhjKekk9KpNyqA5fK8pkP/g7KDNlXXEvznt2OhQGr dDi9UofGStiA+zXeMVnC/LPaoTesvnwzQSK2Cnmpc43qnFh7LuHSs2G6PEhCXPKYkaMn Lg== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2qpb5rqcv6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Feb 2019 11:55:25 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x1LBtP3a022610 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Feb 2019 11:55:25 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x1LBtNG2012028; Thu, 21 Feb 2019 11:55:24 GMT Received: from [192.168.1.67] (/94.61.137.133) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 21 Feb 2019 03:55:23 -0800 Subject: Re: [Xen-devel] [PATCH RFC 00/39] x86/KVM: Xen HVM guest support To: =?UTF-8?Q?Marek_Marczykowski-G=c3=b3recki?= Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Juergen Gross , Stefano Stabellini , xen-devel@lists.xenproject.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , x86@kernel.org, Ankur Arora , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Paolo Bonzini , Boris Ostrovsky , Thomas Gleixner References: <20190220201609.28290-1-joao.m.martins@oracle.com> <20190220233941.GA5279@mail-itl> From: Joao Martins Message-ID: <6c12ea67-0845-d2c2-6f78-f4819b46b7b5@oracle.com> Date: Thu, 21 Feb 2019 11:55:10 +0000 MIME-Version: 1.0 In-Reply-To: <20190220233941.GA5279@mail-itl> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9173 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902210089 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/20/19 11:39 PM, Marek Marczykowski-Górecki wrote: > On Wed, Feb 20, 2019 at 08:15:30PM +0000, Joao Martins wrote: >> 2. PV Driver support (patches 17 - 39) >> >> We start by redirecting hypercalls from the backend to routines >> which emulate the behaviour that PV backends expect i.e. grant >> table and interdomain events. Next, we add support for late >> initialization of xenbus, followed by implementing >> frontend/backend communication mechanisms (i.e. grant tables and >> interdomain event channels). Finally, introduce xen-shim.ko, >> which will setup a limited Xen environment. This uses the added >> functionality of Xen specific shared memory (grant tables) and >> notifications (event channels). > > Does it mean backends could be run in another guest, similarly as on > real Xen? AFAIK virtio doesn't allow that as virtio backends need > arbitrary write access to guest memory. But grant tables provide enough > abstraction to do that safely. > In this series not yet. Here we are trying to resemble how KVM drives its kernel PV backends (i.e. vhost virtio). The domU grant {un,}mapping could be added complementary. The main difference between domU gntmap vs shim gntmap is that the former maps/unmaps the guest page on the backend. Most of it is common code I think. Joao