[RFC PATCH v1 1/9] iommu/kho: Extend IOMMU KHO ABI for ARM SMMUv3
flat view
COOLING5d
From: Pranjal Shrivastava <praan@google.com>
Date: 2026-09-29 07:20:00
Also in:
kexec, linux-iommu, lkml
Subsystem:
kexec handover (kho), live update, the rest · Maintainers:
Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds
Extend the KHO IOMMU ABI to support state preservation for Arm SMMUv3. Introduce struct iommu_smmuv3_hw_ser to capture SMMU hardware state, including the register base, Stream Table config and Live Update state tokens for the preserved Stream Tables. Additionally, introduce struct iommu_master_smmuv3_ser to capture per master state. For now it is used to preserve CD tables for Stage-1 translation. Signed-off-by: Pranjal Shrivastava <praan@google.com> --- include/linux/kho/abi/iommu.h | 36 +++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
diff --git a/include/linux/kho/abi/iommu.h b/include/linux/kho/abi/iommu.h
index 308cd83fd3e3..397fdb0449a6 100644
--- a/include/linux/kho/abi/iommu.h
+++ b/include/linux/kho/abi/iommu.h@@ -82,6 +82,7 @@ enum iommu_type_ser { IOMMU_INVALID, IOMMU_INTEL, + IOMMU_ARM_SMMUV3, }; #define IOMMU_SER_FLAG_DELETED (1 << 0)
@@ -142,6 +143,23 @@ struct iommu_device_intel_ser { u64 max_pasid; } __packed; +/** + * struct iommu_master_smmuv3_ser - SMMUv3 specific device state + * @l1_cdtab_lu_state: Live update state token for the linear/L1 CD table + * @num_l2_cdtables: Number of active L2 CD tables preserved + * @l2_cdtab_lu_states_phys: Physical pointer to an array of u64 LU state tokens + * for the active L2 CD tables (0 if linear) + * + * Note: Currently unused for Stage-2 Live Update. Reserved for future + * preservation of Stage-1 per-device Context Descriptor (CD) tables. + */ +struct iommu_master_smmuv3_ser { + u64 l1_cdtab_lu_state; + u32 num_l2_cdtables; + u32 padding; + u64 l2_cdtab_lu_states_phys; +} __packed; + /** * struct iommu_device_ser - Serialized state of a device * @hdr: Common object header
@@ -159,6 +177,7 @@ struct iommu_device_ser { struct iommu_dev_map_ser domain_iommu_ser; union { struct iommu_device_intel_ser intel; + struct iommu_master_smmuv3_ser smmuv3; }; } __packed;
@@ -181,6 +200,22 @@ struct iommu_intel_ser { u64 context_tables_bitmap[VTD_PRESERVED_BITMAP_LONGS]; }; +/** + * struct iommu_smmuv3_hw_ser - SMMUv3 specific hardware state + * @phys_addr: Physical address of the SMMU register base + * @strtab_base_cfg: STRTAB_BASE_CFG register value + * @l1_strtab_lu_state: Live update state token for the linear table OR the L1 table + * @l2_strtab_lu_states_phys: Physical pointer to an array of u64 LU state tokens + * indexed by L1 index, 0 for L2 tables that aren't + * preserved (0 if linear) + */ +struct iommu_smmuv3_hw_ser { + u64 phys_addr; + u64 strtab_base_cfg; + u64 l1_strtab_lu_state; + u64 l2_strtab_lu_states_phys; +} __packed; + /** * struct iommu_hw_ser - Serialized state of an IOMMU instance * @hdr: Common object header
@@ -194,6 +229,7 @@ struct iommu_hw_ser { u64 type; union { struct iommu_intel_ser intel; + struct iommu_smmuv3_hw_ser smmuv3; }; } __packed;
--
2.56.0.rc1.315.gc6ed9934b7-goog