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X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Apr 2023 13:13:37.5682 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: a0be6b71-28e8-4ba0-78be-08db400eb8c1 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[63.35.35.123];Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: AM7EUR03FT043.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: GV1PR08MB8010 Hi Luca, On this serie I would like to open a discussion on how to handle the vector= size and the corresponding command line / configuration / device tree parameters= . In general the user must either give a vector size it wants or has a soluti= on to just request the maximum supported size. In the current implementation if a size bigger than the supported one is pr= ovided: - we silently disable SVE for dom0 - we silently disable SVE for dom0less - we do not create a guest when done through tools This is not completely coherent and i think we should aim for a coherent be= haviour unless we have arguments for this status. Is there any good reason to silently disable for Dom0 and dom0less only ? I see some possible solutions here: - modify parameter behaviour to use the supported size if parameter is bigg= er than it. This would at least keep SVE enabled if a VM depends on it and could si= mplify some of the handling by using 2048 to use the maximum supported size. - coherently stop if the parameter value is not supported (including if sve= is not supported) - always disable SVE if the parameter value is not supported. To be honest I am not quite sure which solution is better but I am not happ= y with the different kind of behaviour we have right now. What are your thoughts ? Regards Bertrand