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b=kSyIwKa0DN69trHW19/O4YRMQa0zpkCkF85gO4WQ4R4048dIzmLOB3CwiXJ/hdj/tUGuJZLjtDOZlyMD9PUjUzwM3mJM0aycb51c+TC1N0F829AXJsrFiJktsZ/N85pdIdRjXF4NODHiwl8QohbQH3wgX8iJN1WtIuRNkiqFQhcnkqEgc+ZwSmMZ+OcouJwDeYg8T/ylz1HvE+o+ZFRKGHKNPR3MLO7qj5NbIvSc2Y+YI3RheipaAOXQXGQbapgDdsc9L/Y9gHAAn6IDiupLVhubhegawPub96F4drFgt+eAy+Sn1Vcjdbrvy/7PSxBDi/1vQCjCtssPMEWg7e/K5w== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by CY3PR12MB9608.namprd12.prod.outlook.com (2603:10b6:930:102::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.10; Fri, 28 Aug 2026 19:34:46 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%4]) with mapi id 15.21.0360.008; Fri, 28 Aug 2026 19:34:46 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: Re: [PATCH v9 7/7] coco: guest: arm64: Replace dummy CCA device with sysfs ABI From: Jason Gunthorpe To: "Aneesh Kumar K.V (Arm)" Cc: linux-coco@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Greg KH , Jeremy Linton , Jonathan Cameron , Lorenzo Pieralisi , Mark Rutland , Sudeep Holla , Will Deacon , Steven Price , Suzuki K Poulose , Andre Przywara In-Reply-To: <20260805063255.1638614-8-aneesh.kumar@kernel.org> References: <20260805063255.1638614-1-aneesh.kumar@kernel.org> <20260805063255.1638614-8-aneesh.kumar@kernel.org> Date: Fri, 28 Aug 2026 16:34:37 -0300 Message-Id: <178794567780.4159892.18233907484320530327.b4-review@b4> X-Mailer: b4 0.17-dev X-ClientProxiedBy: BLAPR03CA0154.namprd03.prod.outlook.com (2603:10b6:208:32f::28) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|CY3PR12MB9608:EE_ X-MS-Office365-Filtering-Correlation-Id: 9f13323f-7644-48f7-a602-08df053b673e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|376014|7416014|1800799024|10067099003|18002099003|22082099003|4143699003|56012099006|11063799006; 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The > file returns 1 in Realm world and 0 otherwise, similar to the existing s390 > /sys/firmware/uv/prot_virt_guest interface for protected virtualization > guests. Is this the case? the uv code is blocked by: if (!test_facility(158)) return 0; Which AI is telling me means the FW supports "ultravisor", so I think that would be broadly equivilent on ARM to FW supporting RMM. ie don't create a firmware/cca unconditionally, look for some sign that RMM is present first? The rest makes sense to me. -- Jason