It does not relate to multi devices, one device also happens when user
page fault triggers.
iopf_queue_remove_device is called.
rcu_assign_pointer(param->fault_param, NULL);
call trace
[ 304.961312] Call trace:
[ 304.961314] show_stack+0x20/0x38 (C)
[ 304.961319] dump_stack_lvl+0xc0/0xd0
[ 304.961324] dump_stack+0x18/0x28
[ 304.961327] iopf_queue_remove_device+0xb0/0x1f0
[ 304.961331] arm_smmu_remove_master_domain+0x204/0x250
[ 304.961336] arm_smmu_attach_commit+0x64/0x100
[ 304.961338] arm_smmu_attach_dev_nested+0x104/0x1a8
[ 304.961340] __iommu_attach_device+0x2c/0x110
[ 304.961343] __iommu_device_set_domain.isra.0+0x78/0xe0
[ 304.961345] __iommu_group_set_domain_internal+0x78/0x160
[ 304.961347] iommu_replace_group_handle+0x9c/0x150
[ 304.961350] iommufd_fault_domain_replace_dev+0x88/0x120
[ 304.961353] iommufd_device_do_replace+0x190/0x3c0
[ 304.961355] iommufd_device_change_pt+0x270/0x688
[ 304.961357] iommufd_device_replace+0x20/0x38
[ 304.961359] vfio_iommufd_physical_attach_ioas+0x30/0x78
[ 304.961363] vfio_df_ioctl_attach_pt+0xa8/0x188
[ 304.961366] vfio_device_fops_unl_ioctl+0x310/0x990
When page fault triggers:
[ 1016.383578] ------------[ cut here ]-----------
[ 1016.388184] WARNING: CPU: 35 PID: 717 at
drivers/iommu/io-pgfault.c:231 iommu_report_device_fault+0x2c8/0x470