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commitb4392813bbupstream. Currently on book3s-hv, the capability KVM_CAP_SPAPR_TCE_VFIO is only available for KVM Guests running on PowerNV and not for the KVM guests running on pSeries hypervisors. This prevents a pSeries L2 guest from leveraging the in-kernel acceleration for H_PUT_TCE_INDIRECT and H_STUFF_TCE hcalls that results in slow startup times for large memory guests. Support for VFIO on pSeries was restored in commitf431a8cde7("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries"), making it possible to re-enable this capability on pSeries hosts. This change enables KVM_CAP_SPAPR_TCE_VFIO for nested PAPR guests on pSeries, while maintaining the existing behavior on PowerNV. Booting an L2 guest with 128GB of memory shows an average 11% improvement in startup time. Fixes:f431a8cde7("powerpc/iommu: Reimplement the iommu_table_group_ops for pSeries") Cc: stable@vger.kernel.org Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20250220070002.1478849-1-amachhiw@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>