On Thu, May 08, 2025 at 08:02:38PM -0700, Nicolin Chen wrote: > 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 a vsmmu_alloc op and prioritize it in arm_vsmmu_alloc(). > > Reviewed-by: Pranjal Shrivastava <pr...@google.com> > Signed-off-by: Nicolin Chen <nicol...@nvidia.com> > --- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 6 ++++++ > .../iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 17 +++++++++++------ > 2 files changed, 17 insertions(+), 6 deletions(-) > > 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 6b8f0d20dac3..a5835af72417 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_smmu_domain; > > /* MMIO registers */ > #define ARM_SMMU_IDR0 0x0 > @@ -720,6 +721,11 @@ 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); > + struct arm_vsmmu *(*vsmmu_alloc)( > + struct arm_smmu_device *smmu, > + struct arm_smmu_domain *smmu_domain, struct iommufd_ctx *ictx, > + unsigned int viommu_type, > + const struct iommu_user_data *user_data); > };
I think you should put the supported viommu type here in the ops struct and match it here: > + /* Prioritize the impl that may support IOMMU_VIOMMU_TYPE_ARM_SMMUV3 */ > + if (master->smmu->impl_ops && master->smmu->impl_ops->vsmmu_alloc) > + vsmmu = master->smmu->impl_ops->vsmmu_alloc( > + master->smmu, s2_parent, ictx, viommu_type, user_data); instead of the EOPNOTSUPP dance. Either the impl_ops supports the requested viommu as an extension or we are running in the normal mode? Is there a reason to allocate a different viommu if the userspace does not enable the implementation specific features? Jason