[PATCH v7 22/28] iommu/arm-smmu-v3-iommufd: Add vsmmu_size/type and vsmmu_init impl ops

Nicolin Chen
2025-06-26T20:33:20Z

An impl driver might want to allocate its own type of vIOMMU object or the
standard IOMMU_VIOMMU_TYPE_ARM_SMMUV3 by setting up its own SW/HW bits, as
the tegra241-cmdqv driver will add IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV.

Add vsmmu_size/type and vsmmu_init to struct arm_smmu_impl_ops. Prioritize
them in arm_smmu_get_viommu_size() and arm_vsmmu_init().

Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 5 +++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 8 ++++++++
2 files changed, 13 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 7eed5c8c72dd..07589350b2a1 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -16,6 +16,7 @@
#include <linux/sizes.h>

struct arm_smmu_device;
+struct arm_vsmmu;

/* MMIO registers */
#define ARM_SMMU_IDR0 0x0
@@ -720,6 +721,10 @@ struct arm_smmu_impl_ops {
int (*init_structures)(struct arm_smmu_device *smmu);
struct arm_smmu_cmdq *(*get_secondary_cmdq)(
struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
+ const size_t vsmmu_size;
+ const enum iommu_viommu_type vsmmu_type;
+ int (*vsmmu_init)(struct arm_vsmmu *vsmmu,
+ const struct iommu_user_data *user_data);
};

/* An SMMUv3 instance */
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index eb9fe1f6311a..2ab1c6cf4aac 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -416,6 +416,10 @@ size_t arm_smmu_get_viommu_size(struct device *dev,
!(smmu->features & ARM_SMMU_FEAT_S2FWB))
return 0;

+ if (smmu->impl_ops && smmu->impl_ops->vsmmu_size &&
+ viommu_type == smmu->impl_ops->vsmmu_type)
+ return smmu->impl_ops->vsmmu_size;
+
if (viommu_type != IOMMU_VIOMMU_TYPE_ARM_SMMUV3)
return 0;

@@ -439,6 +443,10 @@ int arm_vsmmu_init(struct iommufd_viommu *viommu,
/* FIXME Move VMID allocation from the S2 domain allocation to here */
vsmmu->vmid = s2_parent->s2_cfg.vmid;

+ if (smmu->impl_ops && smmu->impl_ops->vsmmu_init &&
+ viommu->type == smmu->impl_ops->vsmmu_type)
+ return smmu->impl_ops->vsmmu_init(vsmmu, user_data);
+
viommu->ops = &arm_vsmmu_ops;
return 0;
}
--
2.43.0