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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 50AC0C4332B for ; Sat, 21 Mar 2020 00:40:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C6432070A for ; Sat, 21 Mar 2020 00:40:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727733AbgCUAk5 (ORCPT ); Fri, 20 Mar 2020 20:40:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36338 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726867AbgCUAk5 (ORCPT ); Fri, 20 Mar 2020 20:40:57 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02L0XE0K080013 for ; Fri, 20 Mar 2020 20:40:56 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2yvq66ptd2-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 20 Mar 2020 20:40:56 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 21 Mar 2020 00:40:54 -0000 Received: from b06avi18878370.portsmouth.uk.ibm.com (9.149.26.194) by e06smtp03.uk.ibm.com (192.168.101.133) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Sat, 21 Mar 2020 00:40:50 -0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02L0emlp43516332 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 21 Mar 2020 00:40:48 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C2D794203F; Sat, 21 Mar 2020 00:40:48 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6136C42042; Sat, 21 Mar 2020 00:40:47 +0000 (GMT) Received: from oc0525413822.ibm.com (unknown [9.85.223.94]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Sat, 21 Mar 2020 00:40:47 +0000 (GMT) Date: Fri, 20 Mar 2020 17:40:44 -0700 From: Ram Pai To: Laurent Dufour Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, Bharata B Rao Reply-To: Ram Pai References: <20200320102643.15516-1-ldufour@linux.ibm.com> <20200320102643.15516-2-ldufour@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200320102643.15516-2-ldufour@linux.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 20032100-0012-0000-0000-00000394C5B1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20032100-0013-0000-0000-000021D1B0B5 Message-Id: <20200321004044.GA5243@oc0525413822.ibm.com> Subject: Re: [PATCH 1/2] KVM: PPC: Book3S HV: check caller of H_SVM_* Hcalls X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.645 definitions=2020-03-20_08:2020-03-20,2020-03-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 priorityscore=1501 mlxlogscore=999 impostorscore=0 spamscore=0 phishscore=0 clxscore=1011 malwarescore=0 suspectscore=0 bulkscore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003210001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 20, 2020 at 11:26:42AM +0100, Laurent Dufour wrote: > The Hcall named H_SVM_* are reserved to the Ultravisor. However, nothing > prevent a malicious VM or SVM to call them. This could lead to weird result > and should be filtered out. > > Checking the Secure bit of the calling MSR ensure that the call is coming > from either the Ultravisor or a SVM. But any system call made from a SVM > are going through the Ultravisor, and the Ultravisor should filter out > these malicious call. This way, only the Ultravisor is able to make such a > Hcall. > > Cc: Bharata B Rao > Cc: Paul Mackerras > Cc: Benjamin Herrenschmidt > Cc: Michael Ellerman > Signed-off-by: Laurent Dufour Reviewed-by: Ram Pai > --- > arch/powerpc/kvm/book3s_hv.c | 32 +++++++++++++++++++++----------- > 1 file changed, 21 insertions(+), 11 deletions(-) >