IOMMU_HWPT_ALLOC already supports iommu_domain allocation for usersapce.
But it can only allocate a hw_pagetable that associates to a given IOAS,
i.e. only a kernel-managed hw_pagetable of IOMMU_HWPT_TYPE_DEFAULT type.
IOMMU drivers can now support user-managed hw_pagetables, for two-stage
translation use cases, that require user data input from the user space.
Extend the IOMMU_HWPT_ALLOC ioctl to accept non-default hwpt_type with a
type specified user data. Also, update the @pt_id to accept hwpt_id too
besides an ioas_id. Then, pass them to the downstream alloc_fn().
Co-developed-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/iommufd/hw_pagetable.c | 19 ++++++++++++++++++-
include/uapi/linux/iommufd.h | 23 +++++++++++++++++++++--
2 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 90fd65859e28..ab25de149ae6 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -300,6 +300,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
bool flag);
struct iommufd_hw_pagetable *hwpt, *parent;
struct iommu_hwpt_alloc *cmd = ucmd->cmd;
+ struct iommu_user_data *data = NULL;
struct iommufd_object *pt_obj;
struct iommufd_device *idev;
struct iommufd_ioas *ioas;
@@ -308,6 +309,11 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
if (cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT || cmd->__reserved)
return -EOPNOTSUPP;
+ if (!cmd->data_len && cmd->hwpt_type != IOMMU_HWPT_TYPE_DEFAULT)
+ return -EINVAL;
+ if (cmd->flags & IOMMU_HWPT_ALLOC_NEST_PARENT &&
+ cmd->hwpt_type != IOMMU_HWPT_TYPE_DEFAULT)
+ return -EINVAL;
idev = iommufd_get_device(ucmd, cmd->dev_id);
if (IS_ERR(idev))
@@ -340,9 +346,19 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
goto out_put_pt;
}
+ if (cmd->data_len) {
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data) {
+ rc = -ENOMEM;
+ goto out_put_pt;
+ }
+ data->uptr = u64_to_user_ptr(cmd->data_uptr);
+ data->len = cmd->data_len;
+ }
+
mutex_lock(mutex);
hwpt = alloc_fn(ucmd->ictx, pt_obj, idev, cmd->flags,
- IOMMU_HWPT_TYPE_DEFAULT, NULL, false);
+ cmd->hwpt_type, data, false);
if (IS_ERR(hwpt)) {
rc = PTR_ERR(hwpt);
goto out_unlock;
@@ -359,6 +375,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
iommufd_object_abort_and_destroy(ucmd->ictx, &hwpt->obj);
out_unlock:
mutex_unlock(mutex);
+ kfree(data);
out_put_pt:
iommufd_put_object(pt_obj);
out_put_idev:
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 3c8660fe9bb1..c46b1f772f20 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -370,15 +370,31 @@ enum iommu_hwpt_type {
* @size: sizeof(struct iommu_hwpt_alloc)
* @flags: Combination of enum iommufd_hwpt_alloc_flags
* @dev_id: The device to allocate this HWPT for
- * @pt_id: The IOAS to connect this HWPT to
+ * @pt_id: The IOAS or HWPT to connect this HWPT to
* @out_hwpt_id: The ID of the new HWPT
* @__reserved: Must be 0
+ * @hwpt_type: One of enum iommu_hwpt_type
+ * @data_len: Length of the type specific data
+ * @data_uptr: User pointer to the type specific data
*
* Explicitly allocate a hardware page table object. This is the same object
* type that is returned by iommufd_device_attach() and represents the
* underlying iommu driver's iommu_domain kernel object.
*
- * A HWPT will be created with the IOVA mappings from the given IOAS.
+ * A kernel-managed HWPT will be created with the mappings from the given
+ * IOAS via the @pt_id. The @hwpt_type for this allocation can be set to
+ * either IOMMU_HWPT_TYPE_DEFAULT or a pre-defined type corresponding to
+ * an I/O page table type supported by the underlying IOMMU hardware.
+ *
+ * A user-managed HWPT will be created from a given parent HWPT via the
+ * @pt_id, in which the parent HWPT must be allocated previously via the
+ * same ioctl from a given IOAS (@pt_id). In this case, the @hwpt_type
+ * must be set to a pre-defined type corresponding to an I/O page table
+ * type supported by the underlying IOMMU hardware.
+ *
+ * If the @hwpt_type is set to IOMMU_HWPT_TYPE_DEFAULT, @data_len and
+ * @data_uptr should be zero. Otherwise, both @data_len and @data_uptr
+ * must be given.
*/
struct iommu_hwpt_alloc {
__u32 size;
@@ -387,6 +403,9 @@ struct iommu_hwpt_alloc {
__u32 pt_id;
__u32 out_hwpt_id;
__u32 __reserved;
+ __u32 hwpt_type;
+ __u32 data_len;
+ __aligned_u64 data_uptr;
};
#define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)
--
2.34.1
