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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 2D45CC10F26 for ; Mon, 23 Mar 2020 04:23:36 +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 D3BCA20719 for ; Mon, 23 Mar 2020 04:23:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D3BCA20719 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.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 48m1Tf008rzDqwP for ; Mon, 23 Mar 2020 15:23:34 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=bharata@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.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 48m1RB55g1zDqv1 for ; Mon, 23 Mar 2020 15:21:26 +1100 (AEDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02N43OKt039371 for ; Mon, 23 Mar 2020 00:21:24 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ywet16k7f-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 23 Mar 2020 00:21:23 -0400 Received: from localhost by e06smtp01.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) Mon, 23 Mar 2020 04:21:18 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02N4LI7c54526146 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 23 Mar 2020 04:21:18 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EFDE4AE045; Mon, 23 Mar 2020 04:21:17 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A1AFCAE053; Mon, 23 Mar 2020 04:21:16 +0000 (GMT) Received: from in.ibm.com (unknown [9.199.43.35]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Mon, 23 Mar 2020 04:21:16 +0000 (GMT) Date: Mon, 23 Mar 2020 09:51:14 +0530 From: Bharata B Rao To: Laurent Dufour Subject: Re: [PATCH 2/2] KVM: PPC: Book3S HV: H_SVM_INIT_START must call UV_RETURN References: <20200320102643.15516-1-ldufour@linux.ibm.com> <20200320102643.15516-3-ldufour@linux.ibm.com> <20200320112403.GG26049@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-TM-AS-GCONF: 00 x-cbid: 20032304-4275-0000-0000-000003B138A4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20032304-4276-0000-0000-000038C66D81 Message-Id: <20200323042114.GH26049@in.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.645 definitions=2020-03-22_08:2020-03-21, 2020-03-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 bulkscore=0 mlxlogscore=999 adultscore=0 spamscore=0 clxscore=1015 phishscore=0 malwarescore=0 lowpriorityscore=0 mlxscore=0 suspectscore=2 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003230024 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: bharata@linux.ibm.com Cc: linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Mar 20, 2020 at 03:36:05PM +0100, Laurent Dufour wrote: > Le 20/03/2020 à 12:24, Bharata B Rao a écrit : > > On Fri, Mar 20, 2020 at 11:26:43AM +0100, Laurent Dufour wrote: > > > When the call to UV_REGISTER_MEM_SLOT is failing, for instance because > > > there is not enough free secured memory, the Hypervisor (HV) has to call > > > UV_RETURN to report the error to the Ultravisor (UV). Then the UV will call > > > H_SVM_INIT_ABORT to abort the securing phase and go back to the calling VM. > > > > > > If the kvm->arch.secure_guest is not set, in the return path rfid is called > > > but there is no valid context to get back to the SVM since the Hcall has > > > been routed by the Ultravisor. > > > > > > Move the setting of kvm->arch.secure_guest earlier in > > > kvmppc_h_svm_init_start() so in the return path, UV_RETURN will be called > > > instead of rfid. > > > > > > Cc: Bharata B Rao > > > Cc: Paul Mackerras > > > Cc: Benjamin Herrenschmidt > > > Cc: Michael Ellerman > > > Signed-off-by: Laurent Dufour > > > --- > > > arch/powerpc/kvm/book3s_hv_uvmem.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c > > > index 79b1202b1c62..68dff151315c 100644 > > > --- a/arch/powerpc/kvm/book3s_hv_uvmem.c > > > +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c > > > @@ -209,6 +209,8 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) > > > int ret = H_SUCCESS; > > > int srcu_idx; > > > + kvm->arch.secure_guest = KVMPPC_SECURE_INIT_START; > > > + > > > if (!kvmppc_uvmem_bitmap) > > > return H_UNSUPPORTED; > > > @@ -233,7 +235,6 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) > > > goto out; > > > } > > > } > > > - kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_START; > > > > There is an assumption that memory slots would have been registered with UV > > if KVMPPC_SECURE_INIT_START has been done. KVM_PPC_SVM_OFF ioctl will skip > > unregistration and other steps during reboot if KVMPPC_SECURE_INIT_START > > hasn't been done. > > > > Have you checked if that path isn't affected by this change? > > I checked that and didn't find any issue there. > > My only concern was that block: > kvm_for_each_vcpu(i, vcpu, kvm) { > spin_lock(&vcpu->arch.vpa_update_lock); > unpin_vpa_reset(kvm, &vcpu->arch.dtl); > unpin_vpa_reset(kvm, &vcpu->arch.slb_shadow); > unpin_vpa_reset(kvm, &vcpu->arch.vpa); > spin_unlock(&vcpu->arch.vpa_update_lock); > } > > But that seems to be safe. Yes, looks like. > > However I'm not a familiar with the KVM's code, do you think an additional > KVMPPC_SECURE_INIT_* value needed here? May be not as long as UV can handle the unexpected uv_unregister_mem_slot() calls, we are good. Regards, Bharata.