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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?929CfyPDD9i1gJVwtKaKG3nK0fhgEqmvbGXnA5tnbIfzvLxlpDZGVfwSj6KT?= =?us-ascii?Q?fS6lQzMpAxmj8HoU3r9HtEsJY9Lv3VA1wleeCR8nPzsdzBqKKcFz5dvegb86?= =?us-ascii?Q?D4Q/4eSB6INekZdzq4SJonei81cInl8u/7V3xBs6dUr2cp2ijivIepyBX1rl?= =?us-ascii?Q?u6UYbKSnMSKBUnYd1wewml929PKlwCMwL7HK9Bbyjoi1YZi1asriCPr8idlv?= =?us-ascii?Q?TaUchsHQkccljLtaGf+ZZXXYvY779aTTVD4+6vvAzI5WPNG0AquspU4SIRfn?= =?us-ascii?Q?oVPlabh1y8HzUMkb/bG9DizE8pzZ+lmN7QHp6Pq3VNkX+Ug8DRSQXX3SzN1E?= =?us-ascii?Q?tdl824P0vNees9jKhn3MHtAwrBfeiNKXimh4l/ocGGht82soIDzwSnErFi1r?= =?us-ascii?Q?gIYyV/Mg6UevcbdSvRRy7LWfFIHi57oiyGeX0mUxMcNrr/gz3OYEwasSj6I6?= =?us-ascii?Q?deGyr+FZcXzH/foVjbYacoDia2xULhJg9VGZ7XqCJtEKkrU7A/o+2N+3Ex7u?= =?us-ascii?Q?xT042f8+JDFbWk7sX1fjXRidre31oDlnNwPoJesaVE8J76cxqLh92CRGbmH9?= =?us-ascii?Q?Vy2WWELBQNelqfXDz3sfmfYJM7hu4rPgaBmljzOcvbOceC+BxMjRaWn38njG?= =?us-ascii?Q?lXDrjpkcIHhpH/vVQ+IBMAZ6/pM9ZMIc38c6GDghp7+GDkOJOZyIzTAf33n6?= =?us-ascii?Q?TyNnlYWZ01o52ZDM2TCeHZseNcgJZFfT6WWdykmiQLMY8U/qptW7c2XGOdeh?= =?us-ascii?Q?LvrEe/k+o7sxu6xhFVYy5ZJOEw9xUBtzlT1/k9ael2AjHyUKX0ghsFqRbVSE?= =?us-ascii?Q?e90XGKRJs+78bqvOElCb3KP2g3oO82ZkiVKg/LB1Qf3acZ4EPneUxSsukrnd?= =?us-ascii?Q?AQjmKVjSXQfMMtUY9nJxKY89GAiEpTBvvixVxs2mxyNfIELgzXmDOUw5FjrJ?= =?us-ascii?Q?F7NU/H3CCTd1r/hjs9hXYulB9TVlH4dqFJ7KgEwMCHDYWZYI0jaQb1k9T/0o?= =?us-ascii?Q?/T5haOVzLQvbTxWwWp1VW9H5LAwQbEH5X/A0a+gIFislCP8b94715DMf7YOI?= =?us-ascii?Q?bMiwbyF6XxBvOsqC4zStbo23dPoC5RvkWOqshugfAVcitszCiteJxGG8i+HG?= =?us-ascii?Q?3Wk+l5qqoC9JYGM0RHJ8O0LbEVh6RtMklguj4bhA98YwKuMM8x2YTKiTzqWO?= =?us-ascii?Q?iZL4LI88WKzoOTJfp8T3BRNz+GekP5e7pOYvTym+cLHb3FYwb0s0h4KN2U7y?= =?us-ascii?Q?MvdHVXfOkEaTR8XPdiy8DbF1liACdrwQ/OYPnq1IqlfXRZT5OGrrPpigv2K9?= =?us-ascii?Q?1ZkABwJ67oo+1ZuWdTXF/J5m?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7ce63965-45d0-4545-c1ad-08d992f7ca88 X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Oct 2021 11:58:40.3612 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: PR1T47Eq6w+ehXkifTeziQMs/xgmvZBiqGWrz5K9AyTUgaJ+stAj/WObk3wFX2OKBgZp94HRspKqI/WHvqm37g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VE1PR04MB6477 On 19.10.2021 12:41, Roger Pau Monn=C3=A9 wrote: > On Mon, Oct 11, 2021 at 10:17:08AM +0200, Jan Beulich wrote: >> With NPT or shadow in use, the p2m_set_entry() -> p2m_pt_set_entry() -> >> write_p2m_entry() -> p2m_flush_nestedp2m() call sequence triggers a lock >> order violation when the PoD lock is held around it. Hence such flushing >> needs to be deferred. Steal the approach from p2m_change_type_range(). >> >> Similarly for EPT I think ept_set_entry() -> ept_sync_domain() -> >> ept_sync_domain_prepare() -> p2m_flush_nestedp2m() is affected. >=20 > I'm slightly worried by this path because it doesn't seem to > acknowledge defer_nested_flush. Oh, yes. Iirc I did look at that logic, write down the remark, and then forgot to add the conditional to ept_sync_domain_prepare(). The interactions with the real (host) flush are kind of ugly there, though - we then further depend on the ->defer_flush / ->need_flush logic, which is EPT-only. But I think I've convinced myself that this ought to work out. > Maybe the flag should be checked by > p2m_flush_nestedp2m instead of leaving it to the callers? I'm not sure this would be a good idea, as there are more callers. Jan