From patchwork Tue Sep 10 08:29:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharata B Rao X-Patchwork-Id: 1160078 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46SJL61Nffz9s7T for ; Tue, 10 Sep 2019 18:37:02 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46SJL6003dzDqkK for ; Tue, 10 Sep 2019 18:37:01 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org 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 46SJB74rLWzDqZk for ; Tue, 10 Sep 2019 18:30:07 +1000 (AEST) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x8A8RG3M116005 for ; Tue, 10 Sep 2019 04:30:05 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ux7yw8t2y-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 10 Sep 2019 04:30:05 -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) Tue, 10 Sep 2019 09:29:59 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x8A8TvLH51249254 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Sep 2019 08:29:57 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A477E52050; Tue, 10 Sep 2019 08:29:57 +0000 (GMT) Received: from bharata.ibmuc.com (unknown [9.199.35.217]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id A532452052; Tue, 10 Sep 2019 08:29:55 +0000 (GMT) From: Bharata B Rao To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v8 3/8] kvmppc: Shared pages support for secure guests Date: Tue, 10 Sep 2019 13:59:41 +0530 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190910082946.7849-1-bharata@linux.ibm.com> References: <20190910082946.7849-1-bharata@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19091008-4275-0000-0000-00000363DA67 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19091008-4276-0000-0000-000038762D16 Message-Id: <20190910082946.7849-4-bharata@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-09-10_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=812 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1909100085 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: , Cc: linuxram@us.ibm.com, cclaudio@linux.ibm.com, kvm-ppc@vger.kernel.org, Bharata B Rao , linux-mm@kvack.org, jglisse@redhat.com, aneesh.kumar@linux.vnet.ibm.com, paulus@au1.ibm.com, sukadev@linux.vnet.ibm.com, hch@lst.de Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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_uvmem.c | 65 ++++++++++++++++++++++++++++-- 2 files changed, 65 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 2595d0144958..4e98dd992bd1 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -342,6 +342,9 @@ #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_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index a1eccb065ba9..bcecb643a730 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -46,6 +46,7 @@ struct kvmppc_uvmem_page_pvt { unsigned long *rmap; unsigned int lpid; unsigned long gpa; + bool skip_page_out; }; /* @@ -159,6 +160,53 @@ kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, return ret; } +/* + * 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 *uvmem_page; + struct kvmppc_uvmem_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_type(rmap) == KVMPPC_RMAP_UVMEM_PFN) { + uvmem_page = pfn_to_page(*rmap & ~KVMPPC_RMAP_UVMEM_PFN); + pvt = (struct kvmppc_uvmem_page_pvt *) + uvmem_page->zone_device_data; + pvt->skip_page_out = true; + } + + pfn = gfn_to_pfn(kvm, gfn); + if (is_error_noslot_pfn(pfn)) + goto out; + + if (!uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift)) + ret = H_SUCCESS; + kvm_release_pfn_clean(pfn); +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + /* * H_SVM_PAGE_IN: Move page from normal memory to secure memory. */ @@ -177,9 +225,12 @@ 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; srcu_idx = srcu_read_lock(&kvm->srcu); down_read(&kvm->mm->mmap_sem); @@ -252,8 +303,16 @@ kvmppc_svm_page_out(struct vm_area_struct *vma, unsigned long start, 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 function is used in two cases: + * - When HV touches a secure page, for which we do UV_PAGE_OUT + * - When a secure page is converted to shared page, we touch + * the page to essentially unmap the device page. In this + * case we skip page-out. + */ + if (!pvt->skip_page_out) + ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, + page_shift); if (ret == U_SUCCESS) *mig.dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED;