From patchwork Wed Feb 9 18:10:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brijesh Singh X-Patchwork-Id: 12740718 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BE1BC433EF for ; Wed, 9 Feb 2022 18:13:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238967AbiBISNT (ORCPT ); Wed, 9 Feb 2022 13:13:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238902AbiBISMt (ORCPT ); Wed, 9 Feb 2022 13:12:49 -0500 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2063.outbound.protection.outlook.com [40.107.220.63]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6BE4C03FECA; Wed, 9 Feb 2022 10:12:04 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=M9L4f93W1Lr6t41eAHB6eeltgkIyN6jARUluK0rZvW2ymXX3ZdM/+5g/REkIrRVxma4U4UXkxwyEOPNAWadVvAw6ku0x1Wb5e/P81gJJwdW6kyIE5tXLtuUQD4bnLDMwbAQET8Y3WWzKgPeOMcTMf8tpfqXuXOaXhfe6X05yGbxilQT5p66mUIZnwxZasFx9pjtJo5/h3G2rNHZr5c7AO1tRZdxIS2XIudVkS49slLLjaIJ2DKJ5v7TaxR4RUghJumCnST67WvcGRy0deS1frZGLlPphoyyE6uHjCJCDtJ5GQKDIbh7U5ISx9FSVsyIZc8zccHNGgXX5x1v29iC4bw== 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=VIl7FGcVVCCTXlpIwuSotWlAhVTgllnaxmtLpaZNBXA=; b=Y8CsYF+Eax0u2wek3OhgenyePE61X073kl7OegsJfqu8EDsp7M5e/65nrAQ5bHVy6s2HpyxbQF8/zv3id51DYPKZx7JB3KIqCEv/8LXINodrnwAgvH4EDmXMDOFj+sNWX515J18ND65Oi60s7dqgtsOvqS/EsSungbylSxmx7bfuj7TcCB2OQKtotdDchzyldjfP0DCmrhBnBlD+JSuajhEfzs7nhOJz65rBUmFyi2KKR2Sj2bMR6phP7xc9ouyvqGcUzxYL/SBD57kxALV8dU8hTH67LTOhKkvd75xsazIU5fjoC9+wsgmNmb8lLX+no8xxMRVayN1mChMvwDo+1g== 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=VIl7FGcVVCCTXlpIwuSotWlAhVTgllnaxmtLpaZNBXA=; b=R+jVo3ALIn/L7dd5ZYvb+Uy3wRB1lkkJyvnwFzI9ZotMklSQ5zAj87cnG8gJhStJ8gCBUF0uu+3RJEltw+p/L87/mLAJR49G1cpq8cn3jheyupaF7OL0V3LNNaMrYnRAaat9M1B5pzti66vZAFlTyG791gIzASfp2I1spGzi5NI= Received: from BN9PR03CA0879.namprd03.prod.outlook.com (2603:10b6:408:13c::14) by BN6PR12MB1714.namprd12.prod.outlook.com (2603:10b6:404:107::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.12; Wed, 9 Feb 2022 18:12:01 +0000 Received: from BN8NAM11FT063.eop-nam11.prod.protection.outlook.com (2603:10b6:408:13c:cafe::f3) by BN9PR03CA0879.outlook.office365.com (2603:10b6:408:13c::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.12 via Frontend Transport; Wed, 9 Feb 2022 18:12:01 +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; Received: from SATLEXMB04.amd.com (165.204.84.17) by BN8NAM11FT063.mail.protection.outlook.com (10.13.177.110) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.4975.11 via Frontend Transport; Wed, 9 Feb 2022 18:12:01 +0000 Received: from sbrijesh-desktop.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 15.1.2375.18; Wed, 9 Feb 2022 12:11:59 -0600 From: Brijesh Singh To: , , , , , , CC: Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , "Vitaly Kuznetsov" , Jim Mattson , "Andy Lutomirski" , Dave Hansen , Sergio Lopez , Peter Gonda , "Peter Zijlstra" , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , , , , , Brijesh Singh Subject: [PATCH v10 20/45] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Date: Wed, 9 Feb 2022 12:10:14 -0600 Message-ID: <20220209181039.1262882-21-brijesh.singh@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220209181039.1262882-1-brijesh.singh@amd.com> References: <20220209181039.1262882-1-brijesh.singh@amd.com> MIME-Version: 1.0 X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: aa8666a5-2d40-4025-f6ef-08d9ebf7ab9b X-MS-TrafficTypeDiagnostic: BN6PR12MB1714:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:6108; 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:(13230001)(4636009)(36840700001)(40470700004)(46966006)(81166007)(36860700001)(426003)(1076003)(356005)(2616005)(16526019)(186003)(26005)(83380400001)(47076005)(40460700003)(336012)(82310400004)(110136005)(508600001)(70586007)(54906003)(8936002)(7696005)(6666004)(15650500001)(2906002)(7406005)(5660300002)(44832011)(36756003)(7416002)(8676002)(86362001)(70206006)(4326008)(316002)(2101003)(36900700001);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Feb 2022 18:12:01.7116 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: aa8666a5-2d40-4025-f6ef-08d9ebf7ab9b 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: BN8NAM11FT063.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR12MB1714 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org probe_roms() accesses the memory range (0xc0000 - 0x10000) to probe various ROMs. The memory range is not part of the E820 system RAM range. The memory range is mapped as private (i.e encrypted) in page table. When SEV-SNP is active, all the private memory must be validated before the access. The ROM range was not part of E820 map, so the guest BIOS did not validate it. An access to invalidated memory will cause a VC exception. The guest does not support handling not-validated VC exception yet, so validate the ROM memory regions before it is accessed. Signed-off-by: Brijesh Singh --- arch/x86/kernel/probe_roms.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c index 36e84d904260..319fef37d9dc 100644 --- a/arch/x86/kernel/probe_roms.c +++ b/arch/x86/kernel/probe_roms.c @@ -21,6 +21,7 @@ #include #include #include +#include static struct resource system_rom_resource = { .name = "System ROM", @@ -197,11 +198,21 @@ static int __init romchecksum(const unsigned char *rom, unsigned long length) void __init probe_roms(void) { - const unsigned char *rom; unsigned long start, length, upper; + const unsigned char *rom; unsigned char c; int i; + /* + * The ROM memory range is not part of the e820 table and is therefore not + * pre-validated by BIOS. The kernel page table maps the ROM region as encrypted + * memory, and SNP requires encrypted memory to be validated before access. + * Do that here. + */ + snp_prep_memory(video_rom_resource.start, + ((system_rom_resource.end + 1) - video_rom_resource.start), + SNP_PAGE_STATE_PRIVATE); + /* video rom */ upper = adapter_rom_resources[0].start; for (start = video_rom_resource.start; start < upper; start += 2048) {