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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 CF48DC432C3 for ; Wed, 13 Nov 2019 21:50:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BCD85206EE for ; Wed, 13 Nov 2019 21:51:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BCD85206EE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=us.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 21AF26B0006; Wed, 13 Nov 2019 16:50:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1F2906B0008; Wed, 13 Nov 2019 16:50:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 108D06B000A; Wed, 13 Nov 2019 16:50:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0246.hostedemail.com [216.40.44.246]) by kanga.kvack.org (Postfix) with ESMTP id F05AC6B0006 for ; Wed, 13 Nov 2019 16:50:58 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id C88014DCF for ; Wed, 13 Nov 2019 21:50:58 +0000 (UTC) X-FDA: 76152599796.14.arm62_7ccfc235de458 X-HE-Tag: arm62_7ccfc235de458 X-Filterd-Recvd-Size: 6239 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Wed, 13 Nov 2019 21:50:57 +0000 (UTC) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xADLlxah011472 for ; Wed, 13 Nov 2019 16:50:56 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w8sfms9xn-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 13 Nov 2019 16:50:55 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 13 Nov 2019 21:50:50 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xADLoCcn44171756 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Nov 2019 21:50:12 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 09AF94204B; Wed, 13 Nov 2019 21:50:49 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D272C42042; Wed, 13 Nov 2019 21:50:45 +0000 (GMT) Received: from oc0525413822.ibm.com (unknown [9.85.181.122]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 13 Nov 2019 21:50:45 +0000 (GMT) Date: Wed, 13 Nov 2019 13:50:42 -0800 From: Ram Pai To: Paul Mackerras Cc: Bharata B Rao , linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, paulus@au1.ibm.com, aneesh.kumar@linux.vnet.ibm.com, jglisse@redhat.com, cclaudio@linux.ibm.com, sukadev@linux.vnet.ibm.com, hch@lst.de, Sukadev Bhattiprolu , Ram Pai Subject: Re: [PATCH v10 7/8] KVM: PPC: Implement H_SVM_INIT_ABORT hcall Reply-To: Ram Pai References: <20191104041800.24527-8-bharata@linux.ibm.com> <20191111041924.GA4017@oak.ozlabs.ibm.com> <20191112010158.GB5159@oc0525413822.ibm.com> <20191112053836.GB10885@oak.ozlabs.ibm.com> <20191112075215.GD5159@oc0525413822.ibm.com> <20191112113204.GA10178@blackberry> <20191112144555.GE5159@oc0525413822.ibm.com> <20191113001427.GA17829@oak.ozlabs.ibm.com> <20191113063233.GF5159@oc0525413822.ibm.com> <20191113211824.GA20535@blackberry> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191113211824.GA20535@blackberry> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19111321-0020-0000-0000-00000385F2FD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19111321-0021-0000-0000-000021DC0582 Message-Id: <20191113215042.GG5159@oc0525413822.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-13_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound 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=8.0.1-1910280000 definitions=main-1911130180 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Nov 14, 2019 at 08:18:24AM +1100, Paul Mackerras wrote: > On Tue, Nov 12, 2019 at 10:32:33PM -0800, Ram Pai wrote: > > On Wed, Nov 13, 2019 at 11:14:27AM +1100, Paul Mackerras wrote: > > > On Tue, Nov 12, 2019 at 06:45:55AM -0800, Ram Pai wrote: > > > > On Tue, Nov 12, 2019 at 10:32:04PM +1100, Paul Mackerras wrote: > > > > > On Mon, Nov 11, 2019 at 11:52:15PM -0800, Ram Pai wrote: > > > > > > There is subtle problem removing that code from the assembly. > > > > > > > > > > > > If the H_SVM_INIT_ABORT hcall returns to the ultravisor without clearing > > > > > > kvm->arch.secure_guest, the hypervisor will continue to think that the > > > > > > VM is a secure VM. However the primary reason the H_SVM_INIT_ABORT > > > > > > hcall was invoked, was to inform the Hypervisor that it should no longer > > > > > > consider the VM as a Secure VM. So there is a inconsistency there. > > > > > > > > > > Most of the checks that look at whether a VM is a secure VM use code > > > > > like "if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)". Now > > > > > since KVMPPC_SECURE_INIT_ABORT is 4, an if statement such as that will > > > > > take the false branch once we have set kvm->arch.secure_guest to > > > > > KVMPPC_SECURE_INIT_ABORT in kvmppc_h_svm_init_abort. So in fact in > > > > > most places we will treat the VM as a normal VM from then on. If > > > > > there are any places where we still need to treat the VM as a secure > > > > > VM while we are processing the abort we can easily do that too. > > > > > > > > Is the suggestion -- KVMPPC_SECURE_INIT_ABORT should never return back > > > > to the Ultravisor? Because removing that assembly code will NOT lead the > > > > > > No. The suggestion is that vcpu->arch.secure_guest stays set to > > > KVMPPC_SECURE_INIT_ABORT until userspace calls KVM_PPC_SVM_OFF. > > > > In the fast_guest_return path, if it finds > > (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_ABORT) is true, should it return to > > UV or not? > > > > Ideally it should return back to the ultravisor the first time > > KVMPPC_SECURE_INIT_ABORT is set, and not than onwards. > > What is ideal about that behavior? Why would that be a particularly > good thing to do? It is following the rule -- "return back to the caller". RP -- Ram Pai 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 91F77C432C3 for ; Wed, 13 Nov 2019 21:53:12 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6C706206F0 for ; Wed, 13 Nov 2019 21:53:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C706206F0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=us.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47Cyz85hjXzDsNc for ; Thu, 14 Nov 2019 08:53:08 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=us.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=linuxram@us.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=us.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 47Cywg3QVMzF7DR for ; Thu, 14 Nov 2019 08:50:58 +1100 (AEDT) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xADLlweS028335 for ; Wed, 13 Nov 2019 16:50:55 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w8rw0je5v-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 13 Nov 2019 16:50:55 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 13 Nov 2019 21:50:50 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xADLoCcn44171756 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Nov 2019 21:50:12 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 09AF94204B; Wed, 13 Nov 2019 21:50:49 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D272C42042; Wed, 13 Nov 2019 21:50:45 +0000 (GMT) Received: from oc0525413822.ibm.com (unknown [9.85.181.122]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 13 Nov 2019 21:50:45 +0000 (GMT) Date: Wed, 13 Nov 2019 13:50:42 -0800 From: Ram Pai To: Paul Mackerras Subject: Re: [PATCH v10 7/8] KVM: PPC: Implement H_SVM_INIT_ABORT hcall References: <20191104041800.24527-8-bharata@linux.ibm.com> <20191111041924.GA4017@oak.ozlabs.ibm.com> <20191112010158.GB5159@oc0525413822.ibm.com> <20191112053836.GB10885@oak.ozlabs.ibm.com> <20191112075215.GD5159@oc0525413822.ibm.com> <20191112113204.GA10178@blackberry> <20191112144555.GE5159@oc0525413822.ibm.com> <20191113001427.GA17829@oak.ozlabs.ibm.com> <20191113063233.GF5159@oc0525413822.ibm.com> <20191113211824.GA20535@blackberry> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191113211824.GA20535@blackberry> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19111321-0020-0000-0000-00000385F2FD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19111321-0021-0000-0000-000021DC0582 Message-Id: <20191113215042.GG5159@oc0525413822.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-11-13_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound 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=8.0.1-1910280000 definitions=main-1911130180 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Ram Pai Cc: Sukadev Bhattiprolu , cclaudio@linux.ibm.com, kvm-ppc@vger.kernel.org, Bharata B Rao , linux-mm@kvack.org, jglisse@redhat.com, Ram Pai , aneesh.kumar@linux.vnet.ibm.com, paulus@au1.ibm.com, sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, hch@lst.de Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Nov 14, 2019 at 08:18:24AM +1100, Paul Mackerras wrote: > On Tue, Nov 12, 2019 at 10:32:33PM -0800, Ram Pai wrote: > > On Wed, Nov 13, 2019 at 11:14:27AM +1100, Paul Mackerras wrote: > > > On Tue, Nov 12, 2019 at 06:45:55AM -0800, Ram Pai wrote: > > > > On Tue, Nov 12, 2019 at 10:32:04PM +1100, Paul Mackerras wrote: > > > > > On Mon, Nov 11, 2019 at 11:52:15PM -0800, Ram Pai wrote: > > > > > > There is subtle problem removing that code from the assembly. > > > > > > > > > > > > If the H_SVM_INIT_ABORT hcall returns to the ultravisor without clearing > > > > > > kvm->arch.secure_guest, the hypervisor will continue to think that the > > > > > > VM is a secure VM. However the primary reason the H_SVM_INIT_ABORT > > > > > > hcall was invoked, was to inform the Hypervisor that it should no longer > > > > > > consider the VM as a Secure VM. So there is a inconsistency there. > > > > > > > > > > Most of the checks that look at whether a VM is a secure VM use code > > > > > like "if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)". Now > > > > > since KVMPPC_SECURE_INIT_ABORT is 4, an if statement such as that will > > > > > take the false branch once we have set kvm->arch.secure_guest to > > > > > KVMPPC_SECURE_INIT_ABORT in kvmppc_h_svm_init_abort. So in fact in > > > > > most places we will treat the VM as a normal VM from then on. If > > > > > there are any places where we still need to treat the VM as a secure > > > > > VM while we are processing the abort we can easily do that too. > > > > > > > > Is the suggestion -- KVMPPC_SECURE_INIT_ABORT should never return back > > > > to the Ultravisor? Because removing that assembly code will NOT lead the > > > > > > No. The suggestion is that vcpu->arch.secure_guest stays set to > > > KVMPPC_SECURE_INIT_ABORT until userspace calls KVM_PPC_SVM_OFF. > > > > In the fast_guest_return path, if it finds > > (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_ABORT) is true, should it return to > > UV or not? > > > > Ideally it should return back to the ultravisor the first time > > KVMPPC_SECURE_INIT_ABORT is set, and not than onwards. > > What is ideal about that behavior? Why would that be a particularly > good thing to do? It is following the rule -- "return back to the caller". RP -- Ram Pai From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Pai Date: Wed, 13 Nov 2019 21:50:42 +0000 Subject: Re: [PATCH v10 7/8] KVM: PPC: Implement H_SVM_INIT_ABORT hcall Message-Id: <20191113215042.GG5159@oc0525413822.ibm.com> List-Id: References: <20191104041800.24527-8-bharata@linux.ibm.com> <20191111041924.GA4017@oak.ozlabs.ibm.com> <20191112010158.GB5159@oc0525413822.ibm.com> <20191112053836.GB10885@oak.ozlabs.ibm.com> <20191112075215.GD5159@oc0525413822.ibm.com> <20191112113204.GA10178@blackberry> <20191112144555.GE5159@oc0525413822.ibm.com> <20191113001427.GA17829@oak.ozlabs.ibm.com> <20191113063233.GF5159@oc0525413822.ibm.com> <20191113211824.GA20535@blackberry> In-Reply-To: <20191113211824.GA20535@blackberry> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paul Mackerras Cc: Bharata B Rao , linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, paulus@au1.ibm.com, aneesh.kumar@linux.vnet.ibm.com, jglisse@redhat.com, cclaudio@linux.ibm.com, sukadev@linux.vnet.ibm.com, hch@lst.de, Sukadev Bhattiprolu , Ram Pai On Thu, Nov 14, 2019 at 08:18:24AM +1100, Paul Mackerras wrote: > On Tue, Nov 12, 2019 at 10:32:33PM -0800, Ram Pai wrote: > > On Wed, Nov 13, 2019 at 11:14:27AM +1100, Paul Mackerras wrote: > > > On Tue, Nov 12, 2019 at 06:45:55AM -0800, Ram Pai wrote: > > > > On Tue, Nov 12, 2019 at 10:32:04PM +1100, Paul Mackerras wrote: > > > > > On Mon, Nov 11, 2019 at 11:52:15PM -0800, Ram Pai wrote: > > > > > > There is subtle problem removing that code from the assembly. > > > > > > > > > > > > If the H_SVM_INIT_ABORT hcall returns to the ultravisor without clearing > > > > > > kvm->arch.secure_guest, the hypervisor will continue to think that the > > > > > > VM is a secure VM. However the primary reason the H_SVM_INIT_ABORT > > > > > > hcall was invoked, was to inform the Hypervisor that it should no longer > > > > > > consider the VM as a Secure VM. So there is a inconsistency there. > > > > > > > > > > Most of the checks that look at whether a VM is a secure VM use code > > > > > like "if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)". Now > > > > > since KVMPPC_SECURE_INIT_ABORT is 4, an if statement such as that will > > > > > take the false branch once we have set kvm->arch.secure_guest to > > > > > KVMPPC_SECURE_INIT_ABORT in kvmppc_h_svm_init_abort. So in fact in > > > > > most places we will treat the VM as a normal VM from then on. If > > > > > there are any places where we still need to treat the VM as a secure > > > > > VM while we are processing the abort we can easily do that too. > > > > > > > > Is the suggestion -- KVMPPC_SECURE_INIT_ABORT should never return back > > > > to the Ultravisor? Because removing that assembly code will NOT lead the > > > > > > No. The suggestion is that vcpu->arch.secure_guest stays set to > > > KVMPPC_SECURE_INIT_ABORT until userspace calls KVM_PPC_SVM_OFF. > > > > In the fast_guest_return path, if it finds > > (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_ABORT) is true, should it return to > > UV or not? > > > > Ideally it should return back to the ultravisor the first time > > KVMPPC_SECURE_INIT_ABORT is set, and not than onwards. > > What is ideal about that behavior? Why would that be a particularly > good thing to do? It is following the rule -- "return back to the caller". RP -- Ram Pai