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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?8zFNZnDtYmnG6sz8LOBHmXZduT+0Mi9jS0tQJI2ioDtUjgGbXysp4X8ot+fV?= =?us-ascii?Q?EsHf6y6yVOlxUneLI279spYQO8BFN4QzI2XnRz7mymwfId3jMp7aWDaaYQhA?= =?us-ascii?Q?D/XXwnfLAzGq2Ud7H4RlXmvUjYk24jdeG3dcu0XbuK8W7xoougLp9CY4I1mU?= =?us-ascii?Q?lobKrZOCFk90yls9Sj47kFdUk3h0YD7ClrA/w48LDeuKZhGPo4As4fkGww5G?= =?us-ascii?Q?NOn80LXwZ8XGxVHkJs3xTpIBaxO5Xk/5hSD09m6MeZw0iCAqjPxUwR9Z17Ue?= =?us-ascii?Q?MsDC9+YYpmY1mTme87amIW6+XcyydHA2gBapyaxbswjS3HZHlB4oz75c2vE2?= =?us-ascii?Q?2EfYaMfMsxXRn0beuStPa2MbCMqoStpiplegSdlgvIvAPJOrBuqid4sANkTg?= =?us-ascii?Q?xitZhJZ/qoXmqvPDVvZYdFPGgpWzpAZEXko2VkwbSIKZ8JP4SCDZWS8CCe7i?= =?us-ascii?Q?kX/4fbTBuZIkvlpZzjh/YiSCo76RehpEYT2dEX3D+BPWL7F4lEjNT16SUIa0?= =?us-ascii?Q?css2vgEdQdyC9nJUPXyhSSZPH3Nx9irQwQETy4YKDb7KmoLbjerBRnxos1Ar?= =?us-ascii?Q?0IR/L9K1NgrlytE6JkiKczv9aw5nRnUsWidJu6kfqgn7flmsDyA+PykXEwwY?= =?us-ascii?Q?1wJ7w4va7d6P94vxdTkYM2enKlJABt4xVxfB65LrPKtxSXS5vBlWXJsW8tbn?= =?us-ascii?Q?juDC8uqvqYxFBEsKts3Ee/bB8XdlL3DezeNNiX0gcjoP4O6N/vyrO/64B4Qb?= =?us-ascii?Q?nR2zbZBpDN9IHJkeSloa4WNSifDaC5hGozZLQSfs7SPHtV0BsSe7q7YR9l+o?= =?us-ascii?Q?RKk93Y/8j8vYscwmCcUyNCIx9n2DMdGTlteMmoNq3mlVKMicd4ncNanYvAmV?= =?us-ascii?Q?hL60lb7inQFTCBSZqTaw7jaXxUtVSBKbTSQu9jhpOgnxtnx8YQTlSVDrLqCc?= =?us-ascii?Q?qSaTmOjAqIEXI38Eag+royg97UZD1aErDVwE1HxzK4ny39pBVEm1qkKbv716?= =?us-ascii?Q?IBS/Hby7f1xLRVr5pu4jB/6Kbs52wkOng7BIQZp7e1kG8TiHcBlDLyUTC4H4?= =?us-ascii?Q?ucxcbOQdS5hsAViEgDicRvqiPqkPGpiakSyh7g79QqVcGsYcEJqFpsSLsDzj?= =?us-ascii?Q?ZGWgMfspCgGj/bSz8ylBldVF53IyBnLkVVjkk4i7zOFUFODnAFi0lkRKj+DB?= =?us-ascii?Q?WRl6z9YC4JX4jgDtXHAdhCkUh9Zh6jaOCvLIgcXwsuXbGpOWuY2dgL8ICpUU?= =?us-ascii?Q?t7bDjxjxPCL0AInPJmB5KXy9uPAKglztLHSPJp1eP+SH81CP3rLEQbuHh7fR?= =?us-ascii?Q?YQhF1vZBFWZfg7FvkmunGscc7ifA6kzuj3j500hYuu9uEINu1CK3ctpH4mSc?= =?us-ascii?Q?gxyVD32I368kFcNbpfFMuI/K1ZZwNqDN6HCA81ZWkAwtoCNxo9L8MSdxXaam?= =?us-ascii?Q?8lStI++vYX9QSxr0NoGwwCy/gaPFg151WuK0ZAHvtigIp+bk0ae39Vh5rIXA?= =?us-ascii?Q?YgYfNCqcwqEIOvYxFckBCHeTPWBH8kmoAXEUV5MWBPtUagTtRZsXdjyxxTd0?= =?us-ascii?Q?NSjbBheUIg8t8U8GkiZxvnSs+oAMiOf3gM5zvBZ+?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: e64aea56-6ff8-4277-f4a5-08db765007f7 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jun 2023 14:17:10.7795 (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: 8VEOxV6A0UL4RZPF2u6LBzvdYxJat10xGOZXy1h3OUDakBVauiivQi4QdKMZgOH1 X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB8596 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Jun 26, 2023 at 03:36:42PM +0200, Eric Farman wrote: > The pointer to mdev_bus_compat_class is statically defined at the top > of mdev_core, and was originally (commit 7b96953bc640 ("vfio: Mediated > device Core driver") serialized by the parent_list_lock. The blamed > commit removed this mutex, leaving the pointer initialization > unserialized. As a result, the creation of multiple MDEVs in parallel > (such as during boot) can encounter errors during the creation of the > sysfs entries, such as: > > [ 8.337509] sysfs: cannot create duplicate filename '/class/mdev_bus' > [ 8.337514] vfio_ccw 0.0.01d8: MDEV: Registered > [ 8.337516] CPU: 13 PID: 946 Comm: driverctl Not tainted 6.4.0-rc7 #20 > [ 8.337522] Hardware name: IBM 3906 M05 780 (LPAR) > [ 8.337525] Call Trace: > [ 8.337528] [<0000000162b0145a>] dump_stack_lvl+0x62/0x80 > [ 8.337540] [<00000001622aeb30>] sysfs_warn_dup+0x78/0x88 > [ 8.337549] [<00000001622aeca6>] sysfs_create_dir_ns+0xe6/0xf8 > [ 8.337552] [<0000000162b04504>] kobject_add_internal+0xf4/0x340 > [ 8.337557] [<0000000162b04d48>] kobject_add+0x78/0xd0 > [ 8.337561] [<0000000162b04e0a>] kobject_create_and_add+0x6a/0xb8 > [ 8.337565] [<00000001627a110e>] class_compat_register+0x5e/0x90 > [ 8.337572] [<000003ff7fd815da>] mdev_register_parent+0x102/0x130 [mdev] > [ 8.337581] [<000003ff7fdc7f2c>] vfio_ccw_sch_probe+0xe4/0x178 [vfio_ccw] > [ 8.337588] [<0000000162a7833c>] css_probe+0x44/0x80 > [ 8.337599] [<000000016279f4da>] really_probe+0xd2/0x460 > [ 8.337603] [<000000016279fa08>] driver_probe_device+0x40/0xf0 > [ 8.337606] [<000000016279fb78>] __device_attach_driver+0xc0/0x140 > [ 8.337610] [<000000016279cbe0>] bus_for_each_drv+0x90/0xd8 > [ 8.337618] [<00000001627a00b0>] __device_attach+0x110/0x190 > [ 8.337621] [<000000016279c7c8>] bus_rescan_devices_helper+0x60/0xb0 > [ 8.337626] [<000000016279cd48>] drivers_probe_store+0x48/0x80 > [ 8.337632] [<00000001622ac9b0>] kernfs_fop_write_iter+0x138/0x1f0 > [ 8.337635] [<00000001621e5e14>] vfs_write+0x1ac/0x2f8 > [ 8.337645] [<00000001621e61d8>] ksys_write+0x70/0x100 > [ 8.337650] [<0000000162b2bdc4>] __do_syscall+0x1d4/0x200 > [ 8.337656] [<0000000162b3c828>] system_call+0x70/0x98 > [ 8.337664] kobject: kobject_add_internal failed for mdev_bus with -EEXIST, don't try to register things with the same name in the same directory. > [ 8.337668] kobject: kobject_create_and_add: kobject_add error: -17 > [ 8.337674] vfio_ccw: probe of 0.0.01d9 failed with error -12 > [ 8.342941] vfio_ccw_mdev aeb9ca91-10c6-42bc-a168-320023570aea: Adding to iommu group 2 > > Move the initialization of the mdev_bus_compat_class pointer to the > init path, to match the cleanup in module exit. This way the code > in mdev_register_parent() can simply link the new parent to it, > rather than determining whether initialization is required first. > > Fixes: 89345d5177aa ("vfio/mdev: embedd struct mdev_parent in the parent data structure") > Reported-by: Alexander Egorenkov > Signed-off-by: Eric Farman > --- > drivers/vfio/mdev/mdev_core.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) Reviewed-by: Jason Gunthorpe Jason