[PATCH v2 7/8] iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT

Jason Gunthorpe
2024-08-27T15:53:43Z

For SMMUv3 the parent must be a S2 domain, which can be composed
into a IOMMU_DOMAIN_NESTED.

In future the S2 parent will also need a VMID linked to the VIOMMU and
even to KVM.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index ec2fcdd4523a26..8db3db6328f8b7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3103,7 +3103,8 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
const struct iommu_user_data *user_data)
{
struct arm_smmu_master *master = dev_iommu_priv_get(dev);
- const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
+ const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
+ IOMMU_HWPT_ALLOC_NEST_PARENT;
struct arm_smmu_domain *smmu_domain;
int ret;

@@ -3116,6 +3117,14 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
if (!smmu_domain)
return ERR_PTR(-ENOMEM);

+ if (flags & IOMMU_HWPT_ALLOC_NEST_PARENT) {
+ if (!(master->smmu->features & ARM_SMMU_FEAT_NESTING)) {
+ ret = -EOPNOTSUPP;
+ goto err_free;
+ }
+ smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
+ }
+
smmu_domain->domain.type = IOMMU_DOMAIN_UNMANAGED;
smmu_domain->domain.ops = arm_smmu_ops.default_domain_ops;
ret = arm_smmu_domain_finalise(smmu_domain, master->smmu, flags);
--
2.46.0