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Probably by making a > > + * INV_TYPE_S2_VMID_VSMMU */ > > + id = vsmmu->vmid; > > + return 0; > > + } > > Would you mind elaborating why arm_smmu_get_id_from_invs() can't > return vsmmu->vmid to share with a naked S2 STE? A "naked" S2 domain doesn't have a pointer to the vsmmu, so it is impossible to get vsmmu->vmid. The only domains which have it are nested domains using a bypass vSTE. So, if userspace attaches a bypass vSTE then it should use vsmmu->vmid However if they attach a raw S2 HWPT without a vSTE then there is no vsmmu and it should work like any other S2 attach and allocate a VMID for this domain, ignoring any vSMMU that may exist. In sort, the only case where we use the vsmmu->vmid is for vSTEs. Jason