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 D0EF6C3A59F for ; Thu, 29 Aug 2019 07:02:35 +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 5989422CF5 for ; Thu, 29 Aug 2019 07:02:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5989422CF5 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 bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46Jtpc6N4vzDrC5 for ; Thu, 29 Aug 2019 17:02:32 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.156.1; 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 (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 46Jtjv0m6hzDrLb for ; Thu, 29 Aug 2019 16:58:26 +1000 (AEST) Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7T6vu4D129411 for ; Thu, 29 Aug 2019 02:58:23 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2umpb41p27-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 29 Aug 2019 02:58:22 -0400 Received: from localhost by e06smtp03.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) Thu, 29 Aug 2019 07:58:14 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7T6wCV848496758 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 06:58:12 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5F4F1A4066; Thu, 29 Aug 2019 06:58:12 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AEBDBA4054; Thu, 29 Aug 2019 06:58:10 +0000 (GMT) Received: from in.ibm.com (unknown [9.124.35.109]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 29 Aug 2019 06:58:10 +0000 (GMT) Date: Thu, 29 Aug 2019 12:28:08 +0530 From: Bharata B Rao To: Sukadev Bhattiprolu Subject: Re: [PATCH v7 2/7] kvmppc: Shared pages support for secure guests References: <20190822102620.21897-1-bharata@linux.ibm.com> <20190822102620.21897-3-bharata@linux.ibm.com> <20190829030443.GB17497@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829030443.GB17497@us.ibm.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-TM-AS-GCONF: 00 x-cbid: 19082906-0012-0000-0000-00000344289D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19082906-0013-0000-0000-0000217E67C1 Message-Id: <20190829065808.GB31913@in.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-08-29_04:, , 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=721 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290075 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: linuxram@us.ibm.com, cclaudio@linux.ibm.com, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, aneesh.kumar@linux.vnet.ibm.com, paulus@au1.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 Wed, Aug 28, 2019 at 08:04:43PM -0700, Sukadev Bhattiprolu wrote: > > A secure guest will share some of its pages with hypervisor (Eg. virtio > > bounce buffers etc). Support sharing of pages between hypervisor and > > ultravisor. > > > > Once a secure page is converted to shared page, the device page is > > unmapped from the HV side page tables. > > > > Signed-off-by: Bharata B Rao > > --- > > arch/powerpc/include/asm/hvcall.h | 3 ++ > > arch/powerpc/kvm/book3s_hv_devm.c | 70 +++++++++++++++++++++++++++++-- > > 2 files changed, 69 insertions(+), 4 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h > > index 2f6b952deb0f..05b8536f6653 100644 > > --- a/arch/powerpc/include/asm/hvcall.h > > +++ b/arch/powerpc/include/asm/hvcall.h > > @@ -337,6 +337,9 @@ > > #define H_TLB_INVALIDATE 0xF808 > > #define H_COPY_TOFROM_GUEST 0xF80C > > > > +/* Flags for H_SVM_PAGE_IN */ > > +#define H_PAGE_IN_SHARED 0x1 > > + > > /* Platform-specific hcalls used by the Ultravisor */ > > #define H_SVM_PAGE_IN 0xEF00 > > #define H_SVM_PAGE_OUT 0xEF04 > > diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c > > index 13722f27fa7d..6a3229b78fed 100644 > > --- a/arch/powerpc/kvm/book3s_hv_devm.c > > +++ b/arch/powerpc/kvm/book3s_hv_devm.c > > @@ -46,6 +46,7 @@ struct kvmppc_devm_page_pvt { > > unsigned long *rmap; > > unsigned int lpid; > > unsigned long gpa; > > + bool skip_page_out; > > }; > > > > /* > > @@ -139,6 +140,54 @@ kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig, > > return 0; > > } > > > > +/* > > + * Shares the page with HV, thus making it a normal page. > > + * > > + * - If the page is already secure, then provision a new page and share > > + * - If the page is a normal page, share the existing page > > + * > > + * In the former case, uses the dev_pagemap_ops migrate_to_ram handler > > + * to unmap the device page from QEMU's page tables. > > + */ > > +static unsigned long > > +kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift) > > +{ > > + > > + int ret = H_PARAMETER; > > + struct page *devm_page; > > + struct kvmppc_devm_page_pvt *pvt; > > + unsigned long pfn; > > + unsigned long *rmap; > > + struct kvm_memory_slot *slot; > > + unsigned long gfn = gpa >> page_shift; > > + int srcu_idx; > > + > > + srcu_idx = srcu_read_lock(&kvm->srcu); > > + slot = gfn_to_memslot(kvm, gfn); > > + if (!slot) > > + goto out; > > + > > + rmap = &slot->arch.rmap[gfn - slot->base_gfn]; > > + if (kvmppc_rmap_is_devm_pfn(*rmap)) { > > + devm_page = pfn_to_page(*rmap & ~KVMPPC_RMAP_DEVM_PFN); > > + pvt = (struct kvmppc_devm_page_pvt *) > > + devm_page->zone_device_data; > > + pvt->skip_page_out = true; > > + } > > + > > + pfn = gfn_to_pfn(kvm, gpa >> page_shift); > > Use 'gfn'? Yes. > > > + if (is_error_noslot_pfn(pfn)) > > + goto out; > > + > > + ret = uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift); > > + if (ret == U_SUCCESS) > > + ret = H_SUCCESS; > > + kvm_release_pfn_clean(pfn); > > Nit: Blank line? > > +out: > > + srcu_read_unlock(&kvm->srcu, srcu_idx); > > + return ret; > > +} > > + > > /* > > * Move page from normal memory to secure memory. > > */ > > @@ -159,9 +208,12 @@ kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, > > if (page_shift != PAGE_SHIFT) > > return H_P3; > > > > - if (flags) > > + if (flags & ~H_PAGE_IN_SHARED) > > return H_P2; > > > > + if (flags & H_PAGE_IN_SHARED) > > + return kvmppc_share_page(kvm, gpa, page_shift); > > + > > ret = H_PARAMETER; > > down_read(&kvm->mm->mmap_sem); > > srcu_idx = srcu_read_lock(&kvm->srcu); > > @@ -211,7 +263,7 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > > struct page *dpage, *spage; > > struct kvmppc_devm_page_pvt *pvt; > > unsigned long pfn; > > - int ret; > > + int ret = U_SUCCESS; > > > > spage = migrate_pfn_to_page(*mig->src); > > if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE)) > > @@ -226,8 +278,18 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > > pvt = spage->zone_device_data; > > > > pfn = page_to_pfn(dpage); > > - ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, > > - page_shift); > > + > > + /* > > + * This same function is used in two cases: > > Nit: s/same// Extra emphasis :) > > > + * - When HV touches a secure page, for which we do page-out > > Better to qualify page-out with "uv page-out"? its kind of counterintuitive > to do a page-out on a fault! Sure. Regards, Bharata.