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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?z/AsMisV/r5MQMB6Y2AoopSiBm1CkQ+VAGESjuLr17rqi54GGK6Y28ItKjU/?= =?us-ascii?Q?4V6JB4jjaubi7R0wK9ZfQHCrpne+w7/M0Dj0iKJCBvTiGBZnPbvMJQSNgQ8V?= =?us-ascii?Q?JQMVySniGJmsNeovtZ3mXPdg0nIsvBOjFM9txUwNHCYmENfOZwvIXVuUHAWo?= =?us-ascii?Q?afS3U5X88afztwQBXaXbiyN9Zz08jCYmiML2Qwm+O0WPD+CiIEIhLFy0mAN1?= =?us-ascii?Q?q36RCOtCARDR6xeE9tHEkBaevNU0VkNkhMtRVWKWWoCSGkddyA9l4Y1C5LQe?= =?us-ascii?Q?fUsVYvI/brFcYBxKz8jxNnK7fpGDEs8psHbdb19aThnSZwxD/txh4FS81jNv?= =?us-ascii?Q?08EtukVp8+EluiyVyNaeTSglfsaSKjp2mdS+lD111Zm4GtYxRC4DPAGawAnY?= =?us-ascii?Q?jx7z1Hh4jnDXf/KsGseanWfOjWqXWbZGgSNWXxfaW+tfExU+7kvLymQYSVKa?= =?us-ascii?Q?AG3TKrDpp6Swst373qGT1qE8n59sVV3OfVyNDZsSxfuluOcZ+TWjd1WxBJNs?= =?us-ascii?Q?IKDbWUNcz2oeymJCllGu9yn6+99tC530nmnwrBmc4lSIXjK7fAwhnXxc15+I?= =?us-ascii?Q?UjPd5XfawCEhRwBIMRXVaimtAhExF+2erboJ/3QH92tbNe0v1e7Mmaa1N+Px?= =?us-ascii?Q?7zSQ7aotsgjSv8hlRXH/miSh2BCgyRi40qyJRF3/1SYeIAea3pWGlIbCDe4s?= =?us-ascii?Q?S+mcODxJ0s/WyEbMsHV9g/iHomxmBpSMJKHaQRav1pJudXIvx19JWmQq+N3Q?= =?us-ascii?Q?FuBQn4gSl5Wd4dipjoRpKJsaNWIJnfRK5b28twLRz8d4tkGwnd5F5qVSmrnS?= =?us-ascii?Q?Vi392Gg2Xyta7xHCGfB+vjTTMu0WosPHCMI+NHjH0wRhWfGUm4rk9LiZvMuJ?= =?us-ascii?Q?D5PZV4yXsdzcDcBjYh7dXC4p2Sba7eBKZWNEdD6FjCpIVgLNWf0Pt7w3stSM?= =?us-ascii?Q?27iDOPduAtN+0x7MZF34WdcFL5PwHKTZVK2CtkKwK9va97bOBLt4lG3DvAyU?= =?us-ascii?Q?Cj4Nu6vFnPS4visB8Mpc8kwGEzU6kVg+DxahdN1YLTGYyrc+kUxWjtrg1mMD?= =?us-ascii?Q?dwHmJr1ITQ8xlxfrO0hn1U1bPguM9KM085z4v4qP6Nw/GaKafKqSHJi5VSmX?= =?us-ascii?Q?DlwObcrg7pmWiwYImSIDfQaT7Key661/4WJA6aa/uT6rmA+Q9s0oIHD4T0wL?= =?us-ascii?Q?3ISCHT60xWTjrqNIX47BDbgyX8UTuS8Opl3+p3mfwOtUo9/AmKNHBHyHJeuL?= =?us-ascii?Q?V8QMgCV5FmaRK7prsJx4WNW55NN7oUgiDjY0+MbDu7m8n8yjvz0bZs0Z4Pdl?= =?us-ascii?Q?6/RptaIADq2VrX37Ks9l+zEgPTzLS6THRre5hJeNMmfUo+P+M4fAG9AsyupD?= =?us-ascii?Q?8IUPtKvRABsX9TiFasFcwDLid5/W6nd7kBSnYM2tjOLWQQX0LyPV5CodWRaS?= =?us-ascii?Q?k34VtMZCGRPd+PKJD/58AV344rt1ZY0cHVqpH4lQQzKqpuv/38lu/7fSYUR4?= =?us-ascii?Q?3FKM9Ssg4QM1LC8h823PXA4TFvuGliE0DUhaAUCLPABsPuN0KPfJmlWou2pZ?= =?us-ascii?Q?855k7gCeF/yiZlTDfKiLbmlVSO5sDCAB3VEsZaGw?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f6c24d82-b685-4736-460b-08da6a46ee7d X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jul 2022 11:56:50.9507 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 9db/j5Vi3F4ndoo73BxpERTSb7cKiHwNaGhXg/4jMYSm62au2aXQ0vFX4UbS5DB3 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR12MB2664 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Wed, Jul 20, 2022 at 09:47:12AM +0200, Cornelia Huck wrote: > > If the FSM trapped in a bad state here, such as > > VFIO_CCW_STATE_NOT_OPER, then it means it should have already unpinned > > the pages and this is considered a success for this purpose > > A rather pathological case would be a subchannel that cannot be > quiesced and does not end up being non-operational; in theory, the > hardware could still try to access the buffers we provided for I/O. I'd > say that is extremely unlikely, we might log it, but really cannot do > anything else. I think if the FSM can't reach NOT_OPER then it would be appropriate to panic the kernel when it realizes it has lost control of the device. > > The return code here exists only to return to userspace so it can > > detect during a VFIO_DEVICE_RESET that the device has crashed > > irrecoverably. > > Does it imply only that ("it's dead, Jim"), or can it also imply a > runaway device? Not that userspace can do much in any case. The kernel cannot permit a runaway device, the driver must panic if it unable to quiet the device's DMA. I assume this return from RESET is for cases where quieting was successful. Jason