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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED 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 7A8B5C28CC5 for ; Sat, 8 Jun 2019 05:51:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54250208E3 for ; Sat, 8 Jun 2019 05:51:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="BmUtVTTu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730363AbfFHFvN (ORCPT ); Sat, 8 Jun 2019 01:51:13 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:52754 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727044AbfFHFvN (ORCPT ); Sat, 8 Jun 2019 01:51:13 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x585muaV080604; Sat, 8 Jun 2019 05:50:45 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=eCGn2HgXow8RyOmSGWkBzbytLgwPE+mSpcit9XmqcJg=; b=BmUtVTTuGNNgNik7clvsfwJD2ob1DR+D3dt7g1RItTXOp/uLh9UDuVXORqfYGT/Mb+8m wVf3YV7wiSU91qLd+KdAZcTCnHm/NmxswWBOKz6lGa9gmTwrmlBojEuOLfzxEqt6JkgT o7HZDhbuA0AtdzUQtaCer/p3z1iqTyWBoMyaZdFJ4xCA5s+nuY1l51BuFbWLrDXHvvez qOxS4Qj4RmNLVN25ROOynKSXMsoaI98amoUmbtmoYd9uYucDX/dBv4EZ1EemIwUe+ge8 8cPzp2NI/uXS3MNmJnpn86ezY8tHL9+sdriZ/CBNEV1UdwJaj1ZfvX0EoX+q9lu+Jtwq 7Q== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2t04et88eh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 08 Jun 2019 05:50:45 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x585o5db021097; Sat, 8 Jun 2019 05:50:45 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2t04u21jxr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 08 Jun 2019 05:50:44 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x585oh9P031110; Sat, 8 Jun 2019 05:50:43 GMT Received: from [192.168.0.110] (/70.36.60.91) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 07 Jun 2019 22:50:43 -0700 Subject: Re: [Xen-devel] [RFC PATCH 00/16] xenhost support To: Juergen Gross , Joao Martins Cc: sstabellini@kernel.org, konrad.wilk@oracle.com, linux-kernel@vger.kernel.org, pbonzini@redhat.com, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com References: <20190509172540.12398-1-ankur.a.arora@oracle.com> <5649cfd1-24df-2196-2888-b00fc3ace7ad@suse.com> From: Ankur Arora Message-ID: <29e94cec-66ae-baf0-d189-f9487ce162a7@oracle.com> Date: Fri, 7 Jun 2019 22:50:32 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9281 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906080044 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9281 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 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-1906080045 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-06-07 9:21 a.m., Juergen Gross wrote: > On 07.06.19 17:22, Joao Martins wrote: >> On 6/7/19 3:51 PM, Juergen Gross wrote: >>> On 09.05.19 19:25, Ankur Arora wrote: >>>> Hi all, >>>> >>>> This is an RFC for xenhost support, outlined here by Juergen here: >>>> https://lkml.org/lkml/2019/4/8/67. >>> >>> First: thanks for all the effort you've put into this series! >>> >>>> The high level idea is to provide an abstraction of the Xen >>>> communication interface, as a xenhost_t. >>>> >>>> xenhost_t expose ops for communication between the guest and Xen >>>> (hypercall, cpuid, shared_info/vcpu_info, evtchn, grant-table and on >>>> top >>>> of those, xenbus, ballooning), and these can differ based on the kind >>>> of underlying Xen: regular, local, and nested. >>> >>> I'm not sure we need to abstract away hypercalls and cpuid. I believe in >>> case of nested Xen all contacts to the L0 hypervisor should be done via >>> the L1 hypervisor. So we might need to issue some kind of passthrough >>> hypercall when e.g. granting a page to L0 dom0, but this should be >>> handled via the grant abstraction (events should be similar). >>> >> Just to be clear: By "kind of passthrough hypercall" you mean (e.g. >> for every >> access/modify of grant table frames) you would proxy hypercall to L0 >> Xen via L1 Xen? > > It might be possible to spare some hypercalls by directly writing to > grant frames mapped into L1 dom0, but in general you are right. Wouldn't we still need map/unmap_grant_ref? AFAICS, both the xenhost_direct and the xenhost_indirect cases should be very similar (apart from the need to proxy in the indirect case.) Ankur > > > Juergen > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xenproject.org > https://lists.xenproject.org/mailman/listinfo/xen-devel