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Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Mike Rapoport Cc: David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , Liran Alon , Mike Rapoport , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" References: <20201020061859.18385-1-kirill.shutemov@linux.intel.com> <20201020061859.18385-16-kirill.shutemov@linux.intel.com> From: Tom Lendacky Message-ID: <2fe169d4-ce99-1f30-2fea-89d524fe05a8@amd.com> Date: Mon, 26 Oct 2020 14:55:20 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.77.1] X-ClientProxiedBy: DM5PR18CA0082.namprd18.prod.outlook.com (2603:10b6:3:3::20) To DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [10.236.30.118] (165.204.77.1) by DM5PR18CA0082.namprd18.prod.outlook.com (2603:10b6:3:3::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3499.18 via Frontend Transport; Mon, 26 Oct 2020 19:55:21 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-MS-Office365-Filtering-Correlation-Id: f49a43a4-a443-45b4-bcdc-08d879e912fd X-MS-TrafficTypeDiagnostic: DM6PR12MB4043: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:4941; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: FxOZb0N0PLGXWQcm/0BzlkBYVpaFl4RrAFa11YqxsslpPjm9itfvFFR0PKWWXpd5338jjHrB9N6Ek0Z1vzzrxmiI6Tx1751+uNVLC68+AClkYKPyTcd7ui5hTUY8zep7v+5yX3tKyV9eZv2ZGd5fPUyRRcLp7m8dvebb54Sp3zpQNaMDl28EaCmwo/8sHZsO3lb6xy/yMEKj9wdvgOvRY85NtmD0+kzDBHzz5gjT7WGi08jDFziYdtfY6UUEJDsYvSjf+J4p2QJEKs3Rn9aGURatyWQmm+YpOfxwr6PJ9yN9IVhTdl1T0cQQgujgQAAbaZoIkQLv7cxqFKbGKToYXbc2SU8/QW5lYnJNvW6HZ7Cna6DhGNDFbjYbqdB6WoOAbKlEFsPKZ18Pt6EzP9jy0GYRf4eLtcryN8GJOf/KfLqDl44QEdbJVhLKkXjFCxlDn3Z+QRATMIef0XRKAFO8OO5MB93HXRG/i8/iHQCtPeA= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM5PR12MB1355.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(396003)(346002)(376002)(136003)(39860400002)(8936002)(54906003)(45080400002)(110136005)(478600001)(2906002)(26005)(5660300002)(36756003)(966005)(31696002)(86362001)(53546011)(6486002)(2616005)(7416002)(956004)(66946007)(66476007)(52116002)(16576012)(4326008)(16526019)(316002)(31686004)(186003)(8676002)(66556008)(921003)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: f49a43a4-a443-45b4-bcdc-08d879e912fd X-MS-Exchange-CrossTenant-AuthSource: DM5PR12MB1355.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Oct 2020 19:55:22.9693 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: sSGiERkTQvRmIpO23p5N3gR5HR7SMJ5aZQfaWujvNyLJOGoNo+zB2ueJ+3oT9BzLakDbTiuoggpy+y5RDVlkew== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4043 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10/20/20 7:18 AM, David Hildenbrand wrote: > On 20.10.20 08:18, Kirill A. Shutemov wrote: >> If the protected memory feature enabled, unmap guest memory from >> kernel's direct mappings. > > Gah, ugly. I guess this also defeats compaction, swapping, ... oh gosh. > As if all of the encrypted VM implementations didn't bring us enough > ugliness already (SEV extensions also don't support reboots, but can at > least kexec() IIRC). SEV does support reboot. SEV-ES using Qemu doesn't support reboot because of the way Qemu resets the vCPU state. If Qemu could relaunch the guest through the SEV APIs to reset the vCPU state, then a "reboot" would be possible. SEV does support kexec, SEV-ES does not at the moment. Thanks, Tom > > Something similar is done with secretmem [1]. And people don't seem to > like fragmenting the direct mapping (including me). > > [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.kernel.org%2Fr%2F20200924132904.1391-1-rppt%40kernel.org&data=04%7C01%7Cthomas.lendacky%40amd.com%7Cb98a5033da37432131b508d874f25194%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637387931403890525%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BzC%2FeIyOau7BORuUY%2BaiRzYZ%2BOAHANvBDcmV9hpkrts%3D&reserved=0 >