[PATCH v7 02/28] iommufd/viommu: Explicitly define vdev->virt_id

Nicolin Chen
2025-06-26T19:42:31Z

The "id" is too genernal to get its meaning easily. Rename it explicitly to
"virt_id" and update the kdocs for readability. No functional changes.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/iommufd/iommufd_private.h | 7 ++++++-
drivers/iommu/iommufd/driver.c | 2 +-
drivers/iommu/iommufd/viommu.c | 4 ++--
3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 4f5e8cd99c96..09f895638f68 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -634,7 +634,12 @@ struct iommufd_vdevice {
struct iommufd_object obj;
struct iommufd_viommu *viommu;
struct device *dev;
- u64 id; /* per-vIOMMU virtual ID */
+
+ /*
+ * Virtual device ID per vIOMMU, e.g. vSID of ARM SMMUv3, vDeviceID of
+ * AMD IOMMU, and vRID of a nested Intel VT-d to a Context Table
+ */
+ u64 virt_id;
};

#ifdef CONFIG_IOMMUFD_TEST
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 2fee399a148e..887719016804 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -30,7 +30,7 @@ int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
xa_lock(&viommu->vdevs);
xa_for_each(&viommu->vdevs, index, vdev) {
if (vdev->dev == dev) {
- *vdev_id = vdev->id;
+ *vdev_id = vdev->virt_id;
rc = 0;
break;
}
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 25ac08fbb52a..bc8796e6684e 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -111,7 +111,7 @@ void iommufd_vdevice_destroy(struct iommufd_object *obj)
struct iommufd_viommu *viommu = vdev->viommu;

/* xa_cmpxchg is okay to fail if alloc failed xa_cmpxchg previously */
- xa_cmpxchg(&viommu->vdevs, vdev->id, vdev, NULL, GFP_KERNEL);
+ xa_cmpxchg(&viommu->vdevs, vdev->virt_id, vdev, NULL, GFP_KERNEL);
refcount_dec(&viommu->obj.users);
put_device(vdev->dev);
}
@@ -150,7 +150,7 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
goto out_put_idev;
}

- vdev->id = virt_id;
+ vdev->virt_id = virt_id;
vdev->dev = idev->dev;
get_device(idev->dev);
vdev->viommu = viommu;
--
2.43.0