[PATCH v2 06/10] iommu/arm-smmu-v3: Allocate vmid in arm_vsmmu_init

Nicolin Chen
2026-01-22T01:25:02Z

VMID owned by a vSMMU should be allocated in the viommu_init callback, as
HW like tegra241-cmdqv needs to setup VINTF with the VMID.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 +
.../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 21 +++++++++++++++++--
.../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 1 +
3 files changed, 21 insertions(+), 2 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 696ebb89ffa3..8aecdbceb974 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -1190,6 +1190,7 @@ size_t arm_smmu_get_viommu_size(struct device *dev,
int arm_vsmmu_init(struct iommufd_viommu *viommu,
struct iommu_domain *parent_domain,
const struct iommu_user_data *user_data);
+void arm_vsmmu_destroy(struct iommufd_viommu *viommu);
int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,
struct arm_smmu_nested_domain *nested_domain);
void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);
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 34c7bd4cfd84..9998871f69a0 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
@@ -404,7 +404,17 @@ int arm_vsmmu_cache_invalidate(struct iommufd_viommu *viommu,
return ret;
}

+void arm_vsmmu_destroy(struct iommufd_viommu *viommu)
+{
+ struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
+
+ mutex_lock(&arm_smmu_asid_lock);
+ ida_free(&vsmmu->smmu->vmid_map, vsmmu->vmid);
+ mutex_unlock(&arm_smmu_asid_lock);
+}
+
static const struct iommufd_viommu_ops arm_vsmmu_ops = {
+ .destroy = arm_vsmmu_destroy,
.alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
.cache_invalidate = arm_vsmmu_cache_invalidate,
};
@@ -454,14 +464,21 @@ int arm_vsmmu_init(struct iommufd_viommu *viommu,
struct arm_smmu_device *smmu =
container_of(viommu->iommu_dev, struct arm_smmu_device, iommu);
struct arm_smmu_domain *s2_parent = to_smmu_domain(parent_domain);
+ int id;

if (s2_parent->smmu != smmu)
return -EINVAL;

+ mutex_lock(&arm_smmu_asid_lock);
+ id = ida_alloc_range(&smmu->vmid_map, 1, (1 << smmu->vmid_bits) - 1,
+ GFP_KERNEL);
+ mutex_unlock(&arm_smmu_asid_lock);
+ if (id < 0)
+ return id;
+
+ vsmmu->vmid = id;
vsmmu->smmu = smmu;
vsmmu->s2_parent = s2_parent;
- /* FIXME Move VMID allocation from the S2 domain allocation to here */
- vsmmu->vmid = s2_parent->s2_cfg.vmid;

if (viommu->type == IOMMU_VIOMMU_TYPE_ARM_SMMUV3) {
viommu->ops = &arm_vsmmu_ops;
diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index 378104cd395e..67e72115d43a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -1209,6 +1209,7 @@ static void tegra241_cmdqv_destroy_vintf_user(struct iommufd_viommu *viommu)
iommufd_viommu_destroy_mmap(&vintf->vsmmu.core,
vintf->mmap_offset);
tegra241_cmdqv_remove_vintf(vintf->cmdqv, vintf->idx);
+ arm_vsmmu_destroy(viommu);
}

static void tegra241_vintf_destroy_vsid(struct iommufd_vdevice *vdev)
--
2.43.0