From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM10-DM6-obe.outbound.protection.outlook.com (mail-dm6nam10on2083.outbound.protection.outlook.com [40.107.93.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C33C3237 for ; Mon, 20 Jun 2022 23:08:35 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=AH0RNtbF5W8UZLMVQwC3DP9j+/fPhVAU22GbXYNoXkQIFwoRoBa/6CZbx2cNjLGdaY+56IkpvaOAFncAvbMiBhsTNsNImCO7d0Gu3lQfXsbs6yfWSfB5lHoLbxzBgvX9nD4XIPOIFsc8+wkMYlW8f4JakjwQl3+iT0wVBLF+wFGGHu5e69U7PFwcrHeoS9nPN/AYXgQhaFyuZpakEF0RccNyJKJZDOVxaDZ607uwpGGZ2hFUQIOK3WLwR0BIpRY+HnXKlLcvZclxeM3Asdf4r+CsnQvXIzs4N15dhVSERpDyfO2Dyl8sfoOCE+QY7/qANPQgXWCA7yMxeRhUxJxDcg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=H+oYMireA9QI91ofC6K7xSJOx1TFGeE4Gv/InEOiFyE=; b=DJbe/ZIAEPzjXa+cd5YKHCSfXluZ6LbHENC3zQ32KsbPlmXDeifxu9CP0vMCh5/pY/919mjFwAl0xP7UCjg9PqBBSlX5jDJS4B7VKyfAQBucwINC8ptwVD/moGeCbhEfbAp2QJDdBZODntJPtOWD/u9d/NdcQnZZgLvGu3VA5QPEpha93MZDKY6SbJ4YbvGwsacMPh6Wc9S7WBeum/2X7WdwD8KuUKZGyNH6UkHhE5uUHm0NZPra+LrKZFvGAvHKfzNdwyRXH1rTTm8bJBPRDlp4MZGU8GiwEQ0uEsPXKNsJQaT0ei1CEHkSEelpEgkKRVznEhst2lBWxUvb7AXVYA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=kernel.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=H+oYMireA9QI91ofC6K7xSJOx1TFGeE4Gv/InEOiFyE=; b=SrYUSpQ9xiY45c89MN1BQfXCaQLZ4ASTTPvI0l/yRAo9TFtLurZxnBGhGXoUzYBU9T/3Bvx1Bt/zz6RNcTmFvaO5pywfIWLsF4vxoU62jZoaRTGjRYp5bzHj4UNRWP29Nq7R//+7szQAbkl3mXYc0K0yxTv4bbsMEQS5onA48+Q= Received: from DM5PR22CA0013.namprd22.prod.outlook.com (2603:10b6:3:101::23) by DS7PR12MB5909.namprd12.prod.outlook.com (2603:10b6:8:7a::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5353.15; Mon, 20 Jun 2022 23:08:33 +0000 Received: from DM6NAM11FT006.eop-nam11.prod.protection.outlook.com (2603:10b6:3:101:cafe::9f) by DM5PR22CA0013.outlook.office365.com (2603:10b6:3:101::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5353.22 via Frontend Transport; Mon, 20 Jun 2022 23:08:33 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DM6NAM11FT006.mail.protection.outlook.com (10.13.173.104) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.5353.14 via Frontend Transport; Mon, 20 Jun 2022 23:08:33 +0000 Received: from ashkalraubuntuserver.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Mon, 20 Jun 2022 18:08:30 -0500 From: Ashish Kalra To: , , , , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH Part2 v6 27/49] KVM: SVM: Mark the private vma unmerable for SEV-SNP guests Date: Mon, 20 Jun 2022 23:08:22 +0000 Message-ID: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: f7f3ec63-4cf7-43b1-a9dc-08da5311cc52 X-MS-TrafficTypeDiagnostic: DS7PR12MB5909:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230016)(4636009)(376002)(346002)(396003)(136003)(39860400002)(36840700001)(46966006)(40470700004)(16526019)(47076005)(40480700001)(70206006)(86362001)(7696005)(83380400001)(70586007)(26005)(40460700003)(82740400003)(110136005)(316002)(356005)(4326008)(81166007)(6666004)(54906003)(426003)(7416002)(2906002)(82310400005)(336012)(36860700001)(186003)(8936002)(478600001)(7406005)(8676002)(2616005)(36756003)(41300700001)(5660300002)(36900700001)(2101003);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jun 2022 23:08:33.2771 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: f7f3ec63-4cf7-43b1-a9dc-08da5311cc52 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT006.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5909 From: Brijesh Singh When SEV-SNP is enabled, the guest private pages are added in the RMP table; while adding the pages, the rmp_make_private() unmaps the pages from the direct map. If KSM attempts to access those unmapped pages then it will trigger #PF (page-not-present). Encrypted guest pages cannot be shared between the process, so an userspace should not mark the region mergeable but to be safe, mark the process vma unmerable before adding the pages in the RMP table. Signed-off-by: Brijesh Singh --- arch/x86/kvm/svm/sev.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index b5f0707d7ed6..a9461d352eda 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -19,11 +19,13 @@ #include #include #include +#include #include #include #include #include +#include #include "x86.h" #include "svm.h" @@ -1965,6 +1967,30 @@ static bool is_hva_registered(struct kvm *kvm, hva_t hva, size_t len) return false; } +static int snp_mark_unmergable(struct kvm *kvm, u64 start, u64 size) +{ + struct vm_area_struct *vma; + u64 end = start + size; + int ret; + + do { + vma = find_vma_intersection(kvm->mm, start, end); + if (!vma) { + ret = -EINVAL; + break; + } + + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, + MADV_UNMERGEABLE, &vma->vm_flags); + if (ret) + break; + + start = vma->vm_end; + } while (end > vma->vm_end); + + return ret; +} + static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) { struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; @@ -1989,6 +2015,12 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp) if (!is_hva_registered(kvm, params.uaddr, params.len)) return -EINVAL; + mmap_write_lock(kvm->mm); + ret = snp_mark_unmergable(kvm, params.uaddr, params.len); + mmap_write_unlock(kvm->mm); + if (ret) + return -EFAULT; + /* * The userspace memory is already locked so technically we don't * need to lock it again. Later part of the function needs to know -- 2.25.1