Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git

1 files changed, 10 insertions, 2 deletions

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 206fa667c782..010f47f7d3d2 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -776,7 +776,7 @@ enum iommufd_hw_info_flags {
  * @out_data_type: Output the iommu hardware info type as defined in the enum
  *                 iommu_hw_info_type.
  * @out_capabilities: Output the generic iommu capability info type as defined
- *                    in the enum iommu_hw_capabilities.
+ *                    in the enum iommufd_hw_capabilities.
  * @out_max_pasid_log2: Output the width of PASIDs. 0 means no PASID support.
  *                      PCI devices turn to out_capabilities to check if the
  *                      specific capabilities is supported or not.
@@ -871,6 +871,12 @@ enum iommufd_hwpt_get_dirty_bitmap_flags {
  * Walk the IOMMU pagetables for a given IOVA range to return a bitmap
  * with the dirty IOVAs. In doing so it will also by default clear any
  * dirty bit metadata set in the IOPTE.
+ *
+ * The IOVA range given must fully enclose any IOPTE. If the range starts or
+ * ends inside a dirty IOPTE then the ioctl will fail. This avoids partially
+ * reporting a dirty range.
+ *
+ * On failure the dirty state becomes unknown and the userspace must restart.
  */
 struct iommu_hwpt_get_dirty_bitmap {
 	__u32 size;
@@ -948,7 +954,9 @@ struct iommu_hwpt_vtd_s1_invalidate {
  *     CMDQ_OP_CFGI_CD
  *     CMDQ_OP_CFGI_CD_ALL
  *
- * -EIO will be returned if the command is not supported.
+ * User space must forward only valid commands: the kernel rejects, with
+ * -EIO, any command carrying an unsupported opcode, an unsupported field,
+ * or a field value that the underlying SMMU hardware does not implement.
  */
 struct iommu_viommu_arm_smmuv3_invalidate {
 	__aligned_le64 cmd[2];