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

[Nicolin Chen]

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 <nicol...@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