From nobody Fri Dec 19 10:54:41 2025 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2068.outbound.protection.outlook.com [40.107.94.68]) (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 B9CD14084E for ; Tue, 2 Jul 2024 19:57:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.94.68 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950278; cv=fail; b=en810QCZxERuPGw5xQYSKWesAmoq2IWtoApPFOWwG5oF/jx/2a0XRhvW9fk9ayX0Vj9JNErKqiDK9mUQX4nkQuETAODOKkaQKyp5F1VxslpyuuFvYh3sc8ffSKs5WnJpx0MWKhVP8VVicb4bELN8S3JnaiSPrm+PauPaN1mi078= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950278; c=relaxed/simple; bh=KMnNrU51AHoj7SypggOopSsUFQbVOXNKtOWQuOuQMvM=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qSqSDH4kkyZSkOgVHBRk43nYaNSroTtLwZm4XqMEJP8pOE/6CVPNcBMSgsxd8JU7X3ALajYTxTOqfrNdv9RCvS2RvIvjHFLoDIm/KWP8LLFcq2sIq60UWwU+5dX65/33PYU3NdzWDz6NAaRMJ64SULyvGBozGwVFP54exNxbVNk= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=ZvSl+vUU; arc=fail smtp.client-ip=40.107.94.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="ZvSl+vUU" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=c9VK9vdNN2U+9XY/TPU4sMVPSbtW/JB48xPJLa98vd/gjCznfUMx6dkkGl8MiLC/ac6oH4gq9K2LtSYbQXs5TGbi24H8NMK3/8DNuxBFMJdkWI57HAPRlAV221jI+qYJ4qwOmNNRB4qD9wS4QiM72dcWyj7qBUdTYMCcap4ptKYARJQ+zYKAR1tcKXTIpsyG23Xmu+laW+eWb24DjELlTnqGl8M4fmNUFgFQ3O4+7WEFWgoqF7CCy07LxuaEhQg67o/++Felydagq0PWMFitZHcdIPYjdwoX0RESnOLg1h6s0gqz+Mpg8pjWCIFgt55xK8JQVyouGcSaJMn03CVcaQ== 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=xAW6P1BTBJSfNIUvVl8FqTOvvJPB1XAot5xkWOzWcuA=; b=fiwiHkm3A51CVnr6cZ2zYoKNO03m3SJai9V+4AXF5/giq1f13JCqV7QElzTcmcK/Yl2U4zVi53hE+Pm/dn9I8NwYYJu53N5btdEIhluIpTGI45iwtB+MAFAoW1OfsyqKlk/vLIO6fxZpANo6pa42V81MerKjREo7YjqUIn7BZAoPemgtrtm7Xj5f48ze+LBft1UZ3nhfHKbhXjlPSjw7h7MpmvvQ2PmhJI/bhrRtgWlsffB9chJ1xNgeG1yZUopo8JExrMYgQGStxT6k/+U3pZNJ8wUClVmJLw/W1AY6SpKmQ/Bu4xmcfZ3fBY05Hw9dbT85YcoJmjVZ9vQ4v1fKmw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linux.intel.com 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 (0) 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=xAW6P1BTBJSfNIUvVl8FqTOvvJPB1XAot5xkWOzWcuA=; b=ZvSl+vUURV5P/xSetCZ24Jl/qt/wK0y/f422JHSZLR2q5wxcfa7vFz9lzDIjXw3eiaa1KX4rcNMq96aApsfcjS2j67jqCpAS4EGPU/cBYhXSDjrwXnbzN1u9SFBuO9eyraYtc7X0rP4t/JkUOfz73Sj9NDBFNNIqoc3Jesb4Bic= Received: from CH2PR20CA0004.namprd20.prod.outlook.com (2603:10b6:610:58::14) by PH7PR12MB6787.namprd12.prod.outlook.com (2603:10b6:510:1ad::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.33; Tue, 2 Jul 2024 19:57:49 +0000 Received: from CH1PEPF0000AD76.namprd04.prod.outlook.com (2603:10b6:610:58:cafe::8e) by CH2PR20CA0004.outlook.office365.com (2603:10b6:610:58::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.33 via Frontend Transport; Tue, 2 Jul 2024 19:57:49 +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 CH1PEPF0000AD76.mail.protection.outlook.com (10.167.244.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7741.18 via Frontend Transport; Tue, 2 Jul 2024 19:57:48 +0000 Received: from ethanolx7e2ehost.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 15.1.2507.39; Tue, 2 Jul 2024 14:57:47 -0500 From: Ashish Kalra To: , , , , CC: , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v11 1/3] x86/boot: Skip video memory access in the decompressor for SEV-ES/SNP Date: Tue, 2 Jul 2024 19:57:30 +0000 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: <20240614095904.1345461-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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-TrafficTypeDiagnostic: CH1PEPF0000AD76:EE_|PH7PR12MB6787:EE_ X-MS-Office365-Filtering-Correlation-Id: f6158c41-60a4-4869-f942-08dc9ad13fb7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|1800799024|36860700013|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?tbye1GI/sRxulyI8N+5yRNaQ+8sNuzlsr2vwTXihIQri5wdhSKTHi8T8QBKB?= =?us-ascii?Q?aL4UX3+LlTGKg300rovCtDj8hg7BCq7YmQLZtMaPYlTomn92LldtXfQ68COk?= =?us-ascii?Q?rtqY0rCRjfG1CZPcD0cuqwHP/jlWCxvcqaLWsq87WQToPP92xvM0i9x6b4w+?= =?us-ascii?Q?PwCkGgAGQsZ8/Faj1bdewUFNbIaEkHiQ4cXUjswI/tW7e/+okf3RqLbwzH+b?= =?us-ascii?Q?LIJxMIkRpRdmC0GmQHdHVTytqxCkNRek8i4+peEindyvSJ4PqT5iz03oWj3P?= =?us-ascii?Q?cIgrGOidj98xSHsHju+rzFNgC7zqyZmt9w4VH86P3b6mCKKWoTw/OM9GlxUG?= =?us-ascii?Q?W4TL5Mega2x04AFLhABubsKGg4OPRYsJcw17hvBQjV/trnZHvxqjuHmBQSp4?= =?us-ascii?Q?CvsUn7IpcProF6Tkln5yFt1I0pd10Vt0IM+LlSjq7JSdUU06JSSpsJ84US+5?= =?us-ascii?Q?SsvlMi7PYEYxZ/O3ORL+CROtu2FfxaPVm9B/3tzN+xG48mIPCJ4y9p3ApI+x?= =?us-ascii?Q?mdJfWHeRqP3Ll28/y2V8ZP6mxqObwq6RCsDwVaogIgWG9PCUPB79DM5rrz53?= =?us-ascii?Q?0y4g7KzPRe0irYSjbJASY2yFRNboKubRzXFxjr46SzYb5rOvFnEKNi+Uuksx?= =?us-ascii?Q?oYdoejOo7wPjcociz4bjlGPYJ2yjA6SWiaCzkfN7ttfY/6wy8qcUSnfGgYs0?= =?us-ascii?Q?cOgz1B4z+TLUBhS9WmzLW3RbH4qXYqgS1n2wmqd3+SxdtDRNhZB80jMz98uO?= =?us-ascii?Q?ni1JQ17xFHZVohiz4ZzL5f53YkOr0n4nspwEdarWmqcFv+ShZAycl8jKrDom?= =?us-ascii?Q?pB8ZOpuD+GgUIoQxjPvbz3J1xQ+8MFGg7Yfkr4F2v0mnJtQqfNNpUE+aXUKQ?= =?us-ascii?Q?jSEPSjMunaO/XwkGCdGQdZtWBz8B/KKb2ggp7RN0zLDV2UYo8lQFmmQga0mj?= =?us-ascii?Q?Jmh7KyWurBpDHwBAYfIRvwH0h7w57EY8GMKdyU2L9XgkAP+D58AJQLudx8Hy?= =?us-ascii?Q?lW6+omgPo/Ul/Xe0BRw8TXGGxb3Glxhiw2uVB2nJlxJ9evOHoGJjVcAmeBbV?= =?us-ascii?Q?/7P24NmDc3yyg0+WLrovyZ5ECQY5FgRBeXUrCsVHixxYg6S+kkc3aufWYkAu?= =?us-ascii?Q?g0oChA8vOyMKj9qF2bqTg+vydmLqqK6Dj4kgq+WWO/2dciNMUkMcUsy79nQf?= =?us-ascii?Q?u8gd16ivOoqgckmS+ubTszFvQMyP2nDzyjLsDcwpEgDkNAg3gG1e8OhqFfoN?= =?us-ascii?Q?odJRWgcniMrJBHqmEpG250bwRFoLG2jCB5s/5izSA/rRnS28VDwzTw8UD7pw?= =?us-ascii?Q?IOl6qS3c4I+OMo8wsCG9/Nw5KoCxY+NMFuLXogfzrVDiWYjaTRQuHqqQeRjK?= =?us-ascii?Q?4ux9LFXbm9BeLPmvIfwguJVjM+O3YcWXkqcK0WS6/4vRwAaVy/B0NdxLuW6i?= =?us-ascii?Q?bF7UZf6aU6F3NOcEDpXgxcev9rlBxTu0?= 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:(13230040)(82310400026)(1800799024)(36860700013)(7416014)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jul 2024 19:57:48.7006 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: f6158c41-60a4-4869-f942-08dc9ad13fb7 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: CH1PEPF0000AD76.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB6787 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra Accessing guest video memory/RAM in the decompressor causes guest termination as the boot stage2 #VC handler for SEV-ES/SNP systems does not support MMIO handling. This issue is observed during a SEV-ES/SNP guest kexec as kexec -c adds screen_info to the boot parameters passed to the second kernel, which causes console output to be dumped to both video and serial. As the decompressor output gets cleared really fast, it is preferable to get the console output only on serial, hence, skip accessing the video RAM during decompressor stage to prevent guest termination. Serial console output during decompressor stage works as boot stage2 #VC handler already supports handling port I/O. [ bp: Massage. ] Suggested-by: Borislav Petkov (AMD) Suggested-by: Thomas Lendacky Signed-off-by: Ashish Kalra Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Tom Lendacky --- arch/x86/boot/compressed/misc.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/mis= c.c index 944454306ef4..826b4d5cb1f0 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -385,6 +385,19 @@ static void parse_mem_encrypt(struct setup_header *hdr) hdr->xloadflags |=3D XLF_MEM_ENCRYPTION; } =20 +static void early_sev_detect(void) +{ + /* + * Accessing video memory causes guest termination because + * the boot stage2 #VC handler of SEV-ES/SNP guests does not + * support MMIO handling and kexec -c adds screen_info to the + * boot parameters passed to the kexec kernel, which causes + * console output to be dumped to both video and serial. + */ + if (sev_status & MSR_AMD64_SEV_ES_ENABLED) + lines =3D cols =3D 0; +} + /* * The compressed kernel image (ZO), has been moved so that its position * is against the end of the buffer used to hold the uncompressed kernel @@ -440,6 +453,8 @@ asmlinkage __visible void *extract_kernel(void *rmode, = unsigned char *output) */ early_tdx_detect(); =20 + early_sev_detect(); + console_init(); =20 /* --=20 2.34.1 From nobody Fri Dec 19 10:54:41 2025 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2073.outbound.protection.outlook.com [40.107.220.73]) (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 E33624084E for ; Tue, 2 Jul 2024 19:58:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.73 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950297; cv=fail; b=sCl8yJrQ3BBEJrNgiapkycuCcu+Xg/0e4qY4OwRU4YkPEEti7+DfvT7aEgJKl7Pn0cXSVDJgbOdxhJ8+88VqSy/tHxZ+4LedWubS/7xE4HMa0UJjkrK9F78ZMELXuQLaYCeStyOLC9Lm/hg1lcY9P3R5CleFvqQBw8Q2p6j2DXI= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950297; c=relaxed/simple; bh=zatAsJxGxTty56N28Y/nYSj7Vz4vVt3Yp4lteAx20Fo=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZoQDc4YakhseyGDmAABRglmHrwemzma7Q1UOgsYt/l5dHCC+w6waUIjvGV9RpqS0KfivRvOPUfLuRvahA+GXjLBfbvdVpWf74OAj2/a67f3Rk0woI54ezwlvvSL302PzKnZFVg/mKeumOs6kulIHAg3i5b2UO3GDvAF//Ro3qAE= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=gd/02UQR; arc=fail smtp.client-ip=40.107.220.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="gd/02UQR" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=AjjnM1uTAZJdNCm6kbfMbW83DTWl8UKIamjo+fThWXQjUHFSHLaWwbB6cLFKY5zWm+epilpg2Z2DSihF/V8Fx9IVVsKsusG/GLBMUcFbMqoI3HjfVKnnB3+fS2R6KwLeJVWL8QGjLHk2Wco/QWYZLHB6iAL2SlqKjhCIqX0wQmCwmkH7+Hek0WJENr7KEZ6OoqieZ3BrBeP5r3ScnHcUkqTbMzOS3V5eSUS8XYqzhrBE3mWy6Mx0kQyAIFkjNZ4y01rcNBWMOK7IguNRBw0ZJ+dFl2xR4Fr8pncJdR7RaRhsNC5joE5vTVr4ZAnpyan5vr0wPMa8R6DPJ+i3yNzT1Q== 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=E96lfO2ane/Bn+hd5G+CEZvQoyEFIsDM+LjtymPitAA=; b=VBTO7FUBtX/I+xQq/wtmxLAVr4VdK7ZItPXyhVmeZAIxfIChXHH+3IatSiYZC4ch73QFAKnHmMiNV9FG96svJ6n+sKCFLvTtUksAKLP+YgxN3qHiRwldGTisfXgaPVAARYeanDQbjkQ3zVn8TcOx7Cc/Kl5Yqmp1WyF2KtSfslMyMEHZxqVB0PzpqS/LeWujJP0sTrfzr6V0AuSUCpQsLHm86hMKjpho0osF4VSngfQcHyg6Hdxh6HyiSoCfk4olLXaWAgeGNgi0A1Hu1PehCq3jz3F1msMq7QPio7qsQbuAHLV8y5x84sYagEYGFkQhL6cbFfOca9y+OAofISweZw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linux.intel.com 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 (0) 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=E96lfO2ane/Bn+hd5G+CEZvQoyEFIsDM+LjtymPitAA=; b=gd/02UQREsm3Up7W1IrlFdrnEkUeQJ2QD2tcM9xESbialQSLH+S4lnZbUGj1MzRfLdBBTaQtyxXljm3QeACQ0Jv2siqTNkEFQCbj+qgGIz/7TTSHsCHGdeReizUsVWomF2G16Qoc0WPNydDf5nq3DinqQ/v/J7pHe4RWx9mtTdI= Received: from CH2PR20CA0018.namprd20.prod.outlook.com (2603:10b6:610:58::28) by IA1PR12MB6042.namprd12.prod.outlook.com (2603:10b6:208:3d6::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.33; Tue, 2 Jul 2024 19:58:07 +0000 Received: from CH1PEPF0000AD76.namprd04.prod.outlook.com (2603:10b6:610:58:cafe::ae) by CH2PR20CA0018.outlook.office365.com (2603:10b6:610:58::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.34 via Frontend Transport; Tue, 2 Jul 2024 19:58:05 +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 CH1PEPF0000AD76.mail.protection.outlook.com (10.167.244.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7741.18 via Frontend Transport; Tue, 2 Jul 2024 19:58:05 +0000 Received: from ethanolx7e2ehost.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 15.1.2507.39; Tue, 2 Jul 2024 14:58:04 -0500 From: Ashish Kalra To: , , , , CC: , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v11 2/3] x86/mm: refactor __set_clr_pte_enc() Date: Tue, 2 Jul 2024 19:57:54 +0000 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: <20240614095904.1345461-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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-TrafficTypeDiagnostic: CH1PEPF0000AD76:EE_|IA1PR12MB6042:EE_ X-MS-Office365-Filtering-Correlation-Id: 3a2b51be-60a3-402a-350a-08dc9ad14997 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|82310400026|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?PzGjDe/CQtmO1dOBOOzANd6PYFD/m4pZSnTpZtD3sytWg7LzKt2yiNwWozBU?= =?us-ascii?Q?i3jUTmsMHgJhcL7QngfEASegGKvQbOKV4cLerrqIqjkUPVBbKNGPr7yqm2Pa?= =?us-ascii?Q?GvWlDdE3rBkO+DwpMIYXg0Q2/udMNx0Wr8pQI1+a7QsOavHUi7G9EI+l6ntu?= =?us-ascii?Q?b2NgYn4oL3dsh9R4YmCImpkaPzg7uSFazApmEdTg14gsjQV7UvlXtfLbRmUs?= =?us-ascii?Q?By+nvI6Uvnt66JlpXGn9ANEMlSKK6Jm1xbE++1OGItinxLXjy9vn/1i6oBYn?= =?us-ascii?Q?/TlFPlTVVwhPWm3nys+P1RBpZ5a+RVUN9ptfzyoawPwEIFb2CLSNl1b0DSIU?= =?us-ascii?Q?MC3OMTEMSnG5pRALecOIn5SdbxT9kwu1/xR4DeWhKfGM5S7pyGl65cWi8u74?= =?us-ascii?Q?5T3ENznxigXSTqcZJJ61VCjWQHshqfkpPvFmzeYH9qqT5wQBaOFSeAjeULN8?= =?us-ascii?Q?j0NLrX/St7GfkST98pR2kBfb08pnU/75aF2rFXFpcGE+XfkifaJ7olG7oq+v?= =?us-ascii?Q?Cvz/nYKI0vuXjVhgqHWoYL5DHE6Hkfb0GFgYr8SvZ3iHbCW1kMrHwJBkVt6I?= =?us-ascii?Q?l/r2qt0RO4dqBzLSMHNFdB51gL5LKtFwXQJNPQtL3Tt49jykiBiiZyhxXr3N?= =?us-ascii?Q?0TXU+ghWQZY5ZZR8sjv1uoPSFvbfpfBIivXMQqA4uOMvxaNI88d2WvKG9ldv?= =?us-ascii?Q?G81V+kV/9XhWi+Dywd4RZNOcbdse+ArW6Eo/1Ob13nQbtdTM+qimNZ2bUmy8?= =?us-ascii?Q?enTGj5wrZNe4FMMdB26up2VBLM3/CxxkFTqzAeWE8+gsVLLcXpxt3bVR1sfo?= =?us-ascii?Q?+CJbbfOMTHA5cfcy9Y4ci4zcKCO3UwF1vu/MU/+hwu6o9lmmwDl/gAtYAb7k?= =?us-ascii?Q?GsprtOCkVMzjh5HKKYVEN9cODRLFqs9G0W9w6vfqzlXpJ3DSh0MXUXNOcUAI?= =?us-ascii?Q?8QMu0XJ4ogor2SppAf0xagT3vUSUmYEyifyrPPyDmkFW9I3b7lsCrQ5aTbki?= =?us-ascii?Q?SD2/ZNsvFA2qQUGFmUMqd83WciB9M4hcOZ4yhOmeIf6qYF918tY2c+QkaYnZ?= =?us-ascii?Q?SoG/jwv+mWRIFP3GS/0hLyZEPqka5kQHluqKwrwTr4wWzQQUlqYPmwu1pedj?= =?us-ascii?Q?peysz4+9vUu6UK33RArV2I+FJwGCF+OoXTrMEsD/tCjaazKGrreo5qJgbVy8?= =?us-ascii?Q?b9wGIWNKJXxQR1Nz5WU5zmuT65w4vIQooeAUMWsMgxCCNXR9UkDJOnkWAOsj?= =?us-ascii?Q?mlKJrRhYL+gpAIa0RFWtjKWUvYwVjVWuSd7EGUjH4ZIORoKFoCF3gjX0tO6B?= =?us-ascii?Q?HhHMHHLYh/ik31L/r+8Px/vOBq9xPiVOjlmL21dSqvkDyPWhZMZWfTYkEaR/?= =?us-ascii?Q?sQf/Kf/n6Vp58SHpkjPLngW8hmgYb/XsQ88wAOmQXmnAZOgFeqfaL/Q2krpY?= =?us-ascii?Q?gWJDjmvrvWLEDcQN4WfRowDfL8fxLepY?= 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:(13230040)(36860700013)(82310400026)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jul 2024 19:58:05.2631 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 3a2b51be-60a3-402a-350a-08dc9ad14997 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: CH1PEPF0000AD76.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6042 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra Refactor __set_clr_pte_enc() and add two new helper functions to set/clear PTE C-bit from early SEV/SNP initialization code and later during normal system operations and shutdown/kexec. Signed-off-by: Ashish Kalra --- arch/x86/include/asm/sev.h | 9 +++++++ arch/x86/mm/mem_encrypt_amd.c | 47 +++++++++++++++++++++++++++++------ 2 files changed, 48 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index ac5886ce252e..4f3fd913aadb 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -348,6 +348,10 @@ u64 snp_get_unsupported_features(u64 status); u64 sev_get_status(void); void sev_show_status(void); void snp_update_svsm_ca(void); +int prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va, + unsigned long *ret_pfn, unsigned long *ret_pa, + unsigned long *ret_size, pgprot_t *ret_new_prot); +void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot); =20 #else /* !CONFIG_AMD_MEM_ENCRYPT */ =20 @@ -384,6 +388,11 @@ static inline u64 snp_get_unsupported_features(u64 sta= tus) { return 0; } static inline u64 sev_get_status(void) { return 0; } static inline void sev_show_status(void) { } static inline void snp_update_svsm_ca(void) { } +static inline int +prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va, + unsigned long *ret_pfn, unsigned long *ret_pa, + unsigned long *ret_size, pgprot_t *ret_new_prot) { } +static inline void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot= _t new_prot) { } =20 #endif /* CONFIG_AMD_MEM_ENCRYPT */ =20 diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c index 86a476a426c2..42a35040aaf9 100644 --- a/arch/x86/mm/mem_encrypt_amd.c +++ b/arch/x86/mm/mem_encrypt_amd.c @@ -311,15 +311,16 @@ static int amd_enc_status_change_finish(unsigned long= vaddr, int npages, bool en return 0; } =20 -static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) +int prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va, + unsigned long *ret_pfn, unsigned long *ret_pa, + unsigned long *ret_size, pgprot_t *ret_new_prot) { pgprot_t old_prot, new_prot; unsigned long pfn, pa, size; - pte_t new_pte; =20 pfn =3D pg_level_to_pfn(level, kpte, &old_prot); if (!pfn) - return; + return 1; =20 new_prot =3D old_prot; if (enc) @@ -329,7 +330,7 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int l= evel, bool enc) =20 /* If prot is same then do nothing. */ if (pgprot_val(old_prot) =3D=3D pgprot_val(new_prot)) - return; + return 1; =20 pa =3D pfn << PAGE_SHIFT; size =3D page_level_size(level); @@ -339,7 +340,39 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int = level, bool enc) * physical page attribute from C=3D1 to C=3D0 or vice versa. Flush the * caches to ensure that data gets accessed with the correct C-bit. */ - clflush_cache_range(__va(pa), size); + if (va) + clflush_cache_range(va, size); + else + clflush_cache_range(__va(pa), size); + + if (ret_new_prot) + *ret_new_prot =3D new_prot; + if (ret_size) + *ret_size =3D size; + if (ret_pfn) + *ret_pfn =3D pfn; + if (ret_pa) + *ret_pa =3D pa; + + return 0; +} + +void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot) +{ + pte_t new_pte; + + /* Change the page encryption mask. */ + new_pte =3D pfn_pte(pfn, new_prot); + set_pte_atomic(kpte, new_pte); +} + +static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) +{ + unsigned long pfn, pa, size; + pgprot_t new_prot; + + if (prep_set_clr_pte_enc(kpte, level, enc, NULL, &pfn, &pa, &size, &new_p= rot)) + return; =20 /* Encrypt/decrypt the contents in-place */ if (enc) { @@ -354,9 +387,7 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int l= evel, bool enc) early_snp_set_memory_shared((unsigned long)__va(pa), pa, 1); } =20 - /* Change the page encryption mask. */ - new_pte =3D pfn_pte(pfn, new_prot); - set_pte_atomic(kpte, new_pte); + set_pte_enc_mask(kpte, pfn, new_prot); =20 /* * If page is set encrypted in the page table, then update the RMP table = to --=20 2.34.1 From nobody Fri Dec 19 10:54:41 2025 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2050.outbound.protection.outlook.com [40.107.220.50]) (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 850E21CD5D3 for ; Tue, 2 Jul 2024 19:58:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.220.50 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950308; cv=fail; b=bNfyMWqJ0KlXeXndvYZ4rMJCYZ7swYeGCyjMilszRKJTviHFt0DF5Hm2agpxlIIHAGlCzl1FppgJx3mYniRXJFI5qCik4EGimxpmqVyXbJAkkEKgaTK7MjiHuAxRh+ionl1MSrCkt/gCEhSKS0Bz9NANM901vKCWdCEq79dHsb8= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719950308; c=relaxed/simple; bh=ZBOX3UKir4Rdc8d2vQN/PTjcbzNpxnfAWPfrvQSnZew=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZAme+roWxvhcPWpdefuNbBXSpG8EEOXTamQEI6NJBTfhpNaBo/CrimMk6/g+Sj6oGVdR34ubEpyGqXK7gbIvCWq6847RpIcOznQSjC9zl5chEtFy7LD/+on5DctcApF6PD1B/CweVuuiSISmiEL3J9y4itKefGSQIGDj+oQRLxg= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=iNGuQNj0; arc=fail smtp.client-ip=40.107.220.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="iNGuQNj0" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=TeaWozpk7Gsrnr2v+tiNmQnOSmhbH29dOD5bFhQfxB3y3kEtNC+9NBDuWMAkPM6FUS36XQ5H76wMginRwAcVcC0GcUMGBvAJYDSJz4jgkTcvlffeTfs0uO/PQNQ6EHA46VxjgglxHoHtphWbXa2yQ4qJWV4YmJJeRDh5/kzNYeuswf8EnE3yTB/lC1WvUHBZlPdbWAVTKwVwF/ajJQofTz+Aw4exZtOz55Sej5zOjMR0s1bkEqO9TtHdU4qdk1FbrIlERdn8dk/y60LgjN/82kURxiRNCglZcNj7nimgWseECAC6nk9wsBI0ZQdNvlaxuoEWXJTgGVWEXBqWgh58ww== 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=CUrI/eeryUy5zoZTv3MfnzBKWWSINPOUUDd3Dpzpvsk=; b=JJpHK8ryN1RzTKVl8xo9+IAJwS19CkQ/K6bcIe8VEmv43AGM5U7GzsAnQDLtqVgPaPADO8BENM4A+LTNuzbq1Vk4SstpObHhYaTOlXJ4W5hFD+AMmuwszG8rh+32MzURcaNmkHO8eFGBQ8BtFfYNQDt7zte2wFVjrMYzUKyJBvB+ThyySW9QQOTYFIngUuG82AMpT1hCiyljnBupMzyJy+Khvg76osc+MzrKsK8KwnzPXC8fI5tJO7jMIPBtvUAkFnyw2/8g4Z+9xAp9uGosVkWhdGkWxN6XnQdErDDonwLhuRcUYFvUzV+BVODNumBwFvm5ryUf4JBYL4J5o3aDhw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linux.intel.com 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 (0) 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=CUrI/eeryUy5zoZTv3MfnzBKWWSINPOUUDd3Dpzpvsk=; b=iNGuQNj0Ufu+LzxHTcYlTek6KqwDQZMG2zPjcZhllSS52Xg4WHkfZ9XeYem7zSIy3CwC6yfwPcOoZtfXMt8IHQBGKtorcyFcm0BDRTBD/VAdjoLKpOhl1NSQWAvGTDcMTmswd+H90XLUTuRvptk3K5wxUK4uvWrp+wYhxThdnVk= Received: from MN2PR19CA0054.namprd19.prod.outlook.com (2603:10b6:208:19b::31) by IA0PR12MB7676.namprd12.prod.outlook.com (2603:10b6:208:432::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.36; Tue, 2 Jul 2024 19:58:23 +0000 Received: from BL6PEPF0001AB4E.namprd04.prod.outlook.com (2603:10b6:208:19b:cafe::5) by MN2PR19CA0054.outlook.office365.com (2603:10b6:208:19b::31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7719.32 via Frontend Transport; Tue, 2 Jul 2024 19:58:23 +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 BL6PEPF0001AB4E.mail.protection.outlook.com (10.167.242.72) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7741.18 via Frontend Transport; Tue, 2 Jul 2024 19:58:23 +0000 Received: from ethanolx7e2ehost.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 15.1.2507.39; Tue, 2 Jul 2024 14:58:21 -0500 From: Ashish Kalra To: , , , , CC: , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v11 3/3] x86/snp: Convert shared memory back to private on kexec Date: Tue, 2 Jul 2024 19:58:11 +0000 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: <20240614095904.1345461-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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-TrafficTypeDiagnostic: BL6PEPF0001AB4E:EE_|IA0PR12MB7676:EE_ X-MS-Office365-Filtering-Correlation-Id: bad6382a-34fa-4dba-e465-08dc9ad15431 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|36860700013|376014|1800799024|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?bb+LdSJ4Hezdws8iG507zA7kadUGZqvIYGazRppgxcV+yZbobYEK01KrEqv6?= =?us-ascii?Q?idwNqFEWBAJa9HNphPbxUHyQS1S+D7xdhIzw+I34ylY1yy3U+u8tdLD7Zl2d?= =?us-ascii?Q?SexIFL+0L/6re7UQSAlth5rZ4QQxm9VZNsSG+A4SBUjh07/4ClqAvjQp2riU?= =?us-ascii?Q?Z9amJiVGmZ0MoqS9pfz8b5JnWP0h1UjvMghlghKEP4YjBAHLBhrnqKSU5Etu?= =?us-ascii?Q?1wDHWQwSYjCIcvxiJPPrSzSeyW8W2cjrVcmWBzI7rVt6TWBpsAJoUvqUOcMU?= =?us-ascii?Q?FmEbn172dt/3GJnsV7qrO2M66FrNK57ECXJ43HXR7LsyexwvrwreuPjKkKtP?= =?us-ascii?Q?nl3UHQ2j/gDRA+MXzjI3RiIYRaJcB2RN0uD2606t0k9qGWSCwxSPdtNhM8mw?= =?us-ascii?Q?KCnfR436AWRC7w6nznn8eh5wxyC6S0sOh5bqpN8N4UZQzifpIOWt53MKcNNh?= =?us-ascii?Q?ljSgYNsSXVHF4JbrpVpt6yLaM1WxGwWTTnp4PXBGkTXE0JE4wPtJwMDCVvWZ?= =?us-ascii?Q?aZW0+uEml6bl8LZW2hYoUnodki05Bo6x9rIk5v+StJggQKF//eSPJcrwttYz?= =?us-ascii?Q?MMNZgP/OVu56zZtlcvn3u2zA+bpJgcbp48HOnHmBAKqfQs4uboNicQ6SS2cs?= =?us-ascii?Q?oh5uP4xmuBVZtU17pC9TAkBwrm2RiErzCtagQCUpuQjg9DiFxB/2nxFZyZE1?= =?us-ascii?Q?/cJtL34hBUzorgrCLv1ewBznDRhhTZWTRgDv30XYnrhfmTWvSDmie8Lc0ugE?= =?us-ascii?Q?7K/ttbNvAU6UWDClLeKSLAtbAHWPFHMtn0nd4zyn5WVeGk67snZ8fvKgH2Ej?= =?us-ascii?Q?hK2xkKQKC1RC5Pq/oj3iAZLeQ+Z5ydKnadFvnZFU+PTKYO+FnXlGE62ZLxEm?= =?us-ascii?Q?3nZwdbJ+3CsKXc6LBuXu3D1nYfSPzhKs07pviChbj0ROycPncbc4JNpaj/Qh?= =?us-ascii?Q?KK4MMthyc2YFu37uze7Qipwnq9nQTEKgRKL57WhsMF6cWjW5zeZFB9PMgcEa?= =?us-ascii?Q?hHyghTJRkzoQide3SrK19I08yXdSRBv7+pddOenP6GI/p5GNHs3Wkdqb3x4x?= =?us-ascii?Q?YmpJPzf5iHC/YUpNUmpoLp46tIjlZDOrRFb9tNcgGgaxXSk8G8v/8chrodK9?= =?us-ascii?Q?kGEWKpsWltpXosfnYcVW7iqX/LnyP+27LE7jSkJ1yw2u/yIop9o2Q0aw11m1?= =?us-ascii?Q?qA7E7EiiWJTOsifXomVmxA77PfmnNYSIsMvwCOGnLQlbO6UpcFHpEOqay3pE?= =?us-ascii?Q?nUKay8D/Elhx+1FBTWwz+yBKp6s/9w6zhbr79zKDp1F47FNE4U5rZHgXgt2X?= =?us-ascii?Q?GOnkLQPb2rnlBO7uQpHmcmg3y/bKCM/jBPOqD/iY2+Djry/JHIHR1plP8Juj?= =?us-ascii?Q?Y66YqdDC3lMVHDMrVtyVabxgYWz5+aJf5tnKszHfwEnsnBsBk8nKyVDarPUd?= =?us-ascii?Q?bJ12otEz9ywMm74BKAxECYZw8gjOcFaG?= 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:(13230040)(82310400026)(36860700013)(376014)(1800799024)(7416014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jul 2024 19:58:23.0697 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: bad6382a-34fa-4dba-e465-08dc9ad15431 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: BL6PEPF0001AB4E.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB7676 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra SNP guests allocate shared buffers to perform I/O. It is done by allocating pages normally from the buddy allocator and converting them to shared with set_memory_decrypted(). The second, kexec-ed, kernel has no idea what memory is converted this way. It only sees E820_TYPE_RAM. Accessing shared memory via private mapping will cause unrecoverable RMP page-faults. On kexec walk direct mapping and convert all shared memory back to private. It makes all RAM private again and second kernel may use it normally. Additionally for SNP guests convert all bss decrypted section pages back to private. The conversion occurs in two steps: stopping new conversions and unsharing all memory. In the case of normal kexec, the stopping of conversions takes place while scheduling is still functioning. This allows for waiting until any ongoing conversions are finished. The second step is carried out when all CPUs except one are inactive and interrupts are disabled. This prevents any conflicts with code that may access shared memory. Reviewed-by: Tom Lendacky Signed-off-by: Ashish Kalra --- arch/x86/coco/sev/core.c | 148 ++++++++++++++++++++++++++++++++++ arch/x86/include/asm/sev.h | 4 + arch/x86/mm/mem_encrypt_amd.c | 2 + 3 files changed, 154 insertions(+) diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c index 082d61d85dfc..0c90a8a74a88 100644 --- a/arch/x86/coco/sev/core.c +++ b/arch/x86/coco/sev/core.c @@ -1010,6 +1010,154 @@ void snp_accept_memory(phys_addr_t start, phys_addr= _t end) set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE); } =20 +static void set_pte_enc(pte_t *kpte, int level, void *va) +{ + unsigned long pfn; + pgprot_t new_prot; + + prep_set_clr_pte_enc(kpte, level, 1, va, &pfn, NULL, NULL, &new_prot); + set_pte_enc_mask(kpte, pfn, new_prot); +} + +static bool make_pte_private(pte_t *pte, unsigned long addr, int pages, in= t level) +{ + struct sev_es_runtime_data *data; + struct ghcb *ghcb; + int cpu; + + /* + * Ensure that all the per-cpu GHCBs are made private + * at the end of unshared loop so that we continue to use the + * optimized GHCB protocol and not force the switch to + * MSR protocol till the very end. + */ + for_each_possible_cpu(cpu) { + data =3D per_cpu(runtime_data, cpu); + ghcb =3D &data->ghcb_page; + /* Check for GHCB for being part of a PMD range */ + if ((unsigned long)ghcb >=3D addr && + (unsigned long)ghcb <=3D (addr + (pages * PAGE_SIZE))) + return true; + } + + set_pte_enc(pte, level, (void *)addr); + snp_set_memory_private(addr, pages); + + return true; +} + +static void unshare_all_bss_decrypted_memory(void) +{ + unsigned long vaddr, vaddr_end; + unsigned int level; + unsigned int npages; + pte_t *pte; + + vaddr =3D (unsigned long)__start_bss_decrypted; + vaddr_end =3D (unsigned long)__start_bss_decrypted_unused; + npages =3D (vaddr_end - vaddr) >> PAGE_SHIFT; + for (; vaddr < vaddr_end; vaddr +=3D PAGE_SIZE) { + pte =3D lookup_address(vaddr, &level); + if (!pte || !pte_decrypted(*pte) || pte_none(*pte)) + continue; + + set_pte_enc(pte, level, (void *)vaddr); + } + vaddr =3D (unsigned long)__start_bss_decrypted; + snp_set_memory_private(vaddr, npages); +} + +static void unshare_all_memory(void) +{ + unsigned long addr, end; + + /* + * Walk direct mapping and convert all shared memory back to private. + */ + + addr =3D PAGE_OFFSET; + end =3D PAGE_OFFSET + get_max_mapped(); + + while (addr < end) { + unsigned long size; + unsigned int level; + pte_t *pte; + + pte =3D lookup_address(addr, &level); + size =3D page_level_size(level); + + if (pte && pte_decrypted(*pte) && !pte_none(*pte)) { + int pages =3D size / PAGE_SIZE; + + if (!make_pte_private(pte, addr, pages, level)) { + pr_err("Failed to unshare range %#lx-%#lx\n", + addr, addr + size); + } + } + addr +=3D size; + } + + unshare_all_bss_decrypted_memory(); + + __flush_tlb_all(); + +} + +/* Stop new private<->shared conversions */ +void snp_kexec_begin(void) +{ + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return; + + if (!IS_ENABLED(CONFIG_KEXEC_CORE)) + return; + /* + * Crash kernel reaches here with interrupts disabled: can't wait for + * conversions to finish. + * + * If race happened, just report and proceed. + */ + if (!set_memory_enc_stop_conversion()) + pr_warn("Failed to stop shared<->private conversions\n"); +} + +/* Walk direct mapping and convert all shared memory back to private */ +void snp_kexec_finish(void) +{ + struct sev_es_runtime_data *data; + unsigned int level, cpu; + unsigned long size; + struct ghcb *ghcb; + pte_t *pte; + + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return; + + if (!IS_ENABLED(CONFIG_KEXEC_CORE)) + return; + + unshare_all_memory(); + + /* + * Switch to using the MSR protocol to change per-cpu + * GHCBs to private. + * All the per-cpu GHCBs have been switched back to private, + * so can't do any more GHCB calls to the hypervisor beyond + * this point till the kexec kernel starts running. + */ + boot_ghcb =3D NULL; + sev_cfg.ghcbs_initialized =3D false; + + for_each_possible_cpu(cpu) { + data =3D per_cpu(runtime_data, cpu); + ghcb =3D &data->ghcb_page; + pte =3D lookup_address((unsigned long)ghcb, &level); + size =3D page_level_size(level); + set_pte_enc(pte, level, (void *)ghcb); + snp_set_memory_private((unsigned long)ghcb, (size / PAGE_SIZE)); + } +} + static int snp_set_vmsa(void *va, void *caa, int apic_id, bool make_vmsa) { int ret; diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 4f3fd913aadb..4f1a6d1e3f4c 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -352,6 +352,8 @@ int prep_set_clr_pte_enc(pte_t *kpte, int level, int en= c, void *va, unsigned long *ret_pfn, unsigned long *ret_pa, unsigned long *ret_size, pgprot_t *ret_new_prot); void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot); +void snp_kexec_finish(void); +void snp_kexec_begin(void); =20 #else /* !CONFIG_AMD_MEM_ENCRYPT */ =20 @@ -393,6 +395,8 @@ prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, v= oid *va, unsigned long *ret_pfn, unsigned long *ret_pa, unsigned long *ret_size, pgprot_t *ret_new_prot) { } static inline void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot= _t new_prot) { } +static inline void snp_kexec_finish(void) { } +static inline void snp_kexec_begin(void) { } =20 #endif /* CONFIG_AMD_MEM_ENCRYPT */ =20 diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c index 42a35040aaf9..dec24bb08b09 100644 --- a/arch/x86/mm/mem_encrypt_amd.c +++ b/arch/x86/mm/mem_encrypt_amd.c @@ -498,6 +498,8 @@ void __init sme_early_init(void) x86_platform.guest.enc_status_change_finish =3D amd_enc_status_change_fi= nish; x86_platform.guest.enc_tlb_flush_required =3D amd_enc_tlb_flush_requir= ed; x86_platform.guest.enc_cache_flush_required =3D amd_enc_cache_flush_requ= ired; + x86_platform.guest.enc_kexec_begin =3D snp_kexec_begin; + x86_platform.guest.enc_kexec_finish =3D snp_kexec_finish; =20 /* * AMD-SEV-ES intercepts the RDMSR to read the X2APIC ID in the --=20 2.34.1