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X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Apr 2023 14:41:23.5316 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 41d7a528-51ad-4b1c-b625-08db401afb83 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: AM7EUR03FT048.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM9PR08MB6243 > On 18 Apr 2023, at 15:38, Bertrand Marquis wro= te: >=20 > Hi Julien, >=20 >> On 18 Apr 2023, at 16:25, Julien Grall wrote: >>=20 >>=20 >>=20 >> On 18/04/2023 14:13, Bertrand Marquis wrote: >>> Hi Luca, >>=20 >> Hi, >>=20 >>> On this serie I would like to open a discussion on how to handle the ve= ctor size >>> and the corresponding command line / configuration / device tree parame= ters. >>> In general the user must either give a vector size it wants or has a so= lution to >>> just request the maximum supported size. >>> In the current implementation if a size bigger than the supported one i= s provided: >>> - 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 coheren= t behaviour >>> unless we have arguments for this status. >>=20 >> +1. >>=20 >>> 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 = bigger than >>> it. This would at least keep SVE enabled if a VM depends on it and coul= d simplify >>> some of the handling by using 2048 to use the maximum supported size. >>=20 >> My concern with this approach and the third one is the user may take som= e time to realize the problem in the xl.cfg. So... >=20 > Good point >=20 >>=20 >>> - coherently stop if the parameter value is not supported (including if= sve is >>> not supported) >>=20 >> ... this is my preferred approach because it would be clear that the val= ue passed to Xen is bogus. >=20 > I agree: we should not silently ignore configuration parameters or try to= "fix" them. Hi Bertrand and Julien, Ok I will update the serie to stop the domain creation if the parameter sup= plied is wrong or SVE is not supported by the platform. >=20 > Cheers > Bertrand