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Crudup" , "Peter Zijlstra (Intel)" , Paolo Bonzini , Jessica Yu , Fenghua Yu , Xiaoyao Li , Nadav Amit , Thomas Hellstrom , Sean Christopherson , Tony Luck , Steven Rostedt References: <20200402123258.895628824@linutronix.de> <20200402124205.242674296@linutronix.de> From: Rasmus Villemoes Message-ID: Date: Fri, 3 Apr 2020 01:42:33 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 In-Reply-To: <20200402124205.242674296@linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BEXP281CA0018.DEUP281.PROD.OUTLOOK.COM (2603:10a6:b10::28) To VI1PR10MB2765.EURPRD10.PROD.OUTLOOK.COM (2603:10a6:803:e1::21) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.1.149] (5.186.116.45) by BEXP281CA0018.DEUP281.PROD.OUTLOOK.COM (2603:10a6:b10::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2878.15 via Frontend Transport; Thu, 2 Apr 2020 23:42:35 +0000 X-Originating-IP: [5.186.116.45] X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: cd49d0d2-fabc-456c-d83e-08d7d75f8588 X-MS-TrafficTypeDiagnostic: VI1PR10MB2190: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8882; X-Forefront-PRVS: 0361212EA8 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR10MB2765.EURPRD10.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFTY:;SFS:(10019020)(39850400004)(396003)(366004)(376002)(346002)(136003)(956004)(86362001)(31696002)(478600001)(52116002)(7416002)(2906002)(36756003)(81156014)(81166006)(8676002)(5660300002)(66476007)(16576012)(110136005)(66946007)(6486002)(44832011)(16526019)(8936002)(186003)(26005)(2616005)(316002)(31686004)(4326008)(4744005)(66556008)(54906003)(8976002);DIR:OUT;SFP:1102; Received-SPF: None (protection.outlook.com: prevas.dk does not designate permitted sender hosts) X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: zGtK0nx0MvdNLXvG9qcdRsLAOKcL+AlUhLLLZj8BHHtWgLzYr+bFZj2MYxRfce9AnrWEEx/r80hLL0RWRVtbIHsbgjIc8BJb0JOsncRCKh4gWjwO49KVR/O5G/qBQZsVFCnhYN4f4YXevAUVq5FvdZKFJAI+deqosmQ2n5lGyM9CXvfewyI5SeH6bfVDz4WHIJuSLNa32FM8fPDjRiMGIR7ToWxfvlGnV0BI8LfYDcVbqYWYZ6eHe2kouuv7lqsvnwUlwxxhrjsa071m/6rNhIsvkjrFiYJrQPOmBXlxw5XQlh/tyXfPTJXtqAafRIfBnX+zIDMylgd+URejUl7XHP0d3jSU8KsxwVXsi8VmYfYH/fT4eIMmscEoCWYyMJ2b7DZb+0SyEvtUcQq5Y3jQ31Xuuo2oZPfHa0L403jT4E4YFeIH3VR8nMCZpRLp5oDw X-MS-Exchange-AntiSpam-MessageData: 735FzlMSS16ciuaISdaVRsVKFkhJGouUMLaJa98fh2R0In3R/JjBd8zolnP17qM5d22PCIa5BVPQeywgzcL+lZPRhtG5J3inKRkj/lPe2lKF24iAcqF64JdvsAlGQQiaRVyTWk018rRspGmqp8M95g== X-OriginatorOrg: prevas.dk X-MS-Exchange-CrossTenant-Network-Message-Id: cd49d0d2-fabc-456c-d83e-08d7d75f8588 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Apr 2020 23:42:36.1225 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: d350cf71-778d-4780-88f5-071a4cb1ed61 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: CsjcpAUCOLCkTE7AX6mAvkhluE58rfNoTp9DRjTueoS2UFqDmtlu1KMDOqpRzDC2QpC3Lri8ia42l1q1cnNehmR3ItdiJe7q+PUACdbKoIk= X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR10MB2190 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04/2020 14.32, Thomas Gleixner wrote: > From: Peter Zijlstra > > It turns out that with Split-Lock-Detect enabled (default) any VMX > hypervisor needs at least a little modification in order to not blindly > inject the #AC into the guest without the guest being ready for it. > > Since there is no telling which module implements a hypervisor, scan the > module text and look for the VMLAUNCH instruction. If found, the module is > assumed to be a hypervisor of some sort and SLD is disabled. How long does that scan take/add to module load time? Would it make sense to exempt in-tree modules? Rasmus