util: add iova_tree_find_iova

This function does the reverse operation of iova_tree_find: To look for
a mapping that match a translated address so we can do the reverse.

This have linear complexity instead of logarithmic, but it supports
overlapping HVA. Future developments could reduce it.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/include/qemu/iova-tree.h b/include/qemu/iova-tree.h
index d066400..c938fb0 100644
--- a/include/qemu/iova-tree.h
+++ b/include/qemu/iova-tree.h
@@ -83,7 +83,7 @@ int iova_tree_remove(IOVATree *tree, const DMAMap *map);
  * @tree: the iova tree to search from
  * @map: the mapping to search
  *
- * Search for a mapping in the iova tree that overlaps with the
+ * Search for a mapping in the iova tree that iova overlaps with the
  * mapping range specified.  Only the first found mapping will be
  * returned.
  *
@@ -96,6 +96,24 @@ int iova_tree_remove(IOVATree *tree, const DMAMap *map);
 const DMAMap *iova_tree_find(const IOVATree *tree, const DMAMap *map);
 
 /**
+ * iova_tree_find_iova:
+ *
+ * @tree: the iova tree to search from
+ * @map: the mapping to search
+ *
+ * Search for a mapping in the iova tree that translated_addr overlaps with the
+ * mapping range specified.  Only the first found mapping will be
+ * returned.
+ *
+ * Return: DMAMap pointer if found, or NULL if not found.  Note that
+ * the returned DMAMap pointer is maintained internally.  User should
+ * only read the content but never modify or free the content.  Also,
+ * user is responsible to make sure the pointer is valid (say, no
+ * concurrent deletion in progress).
+ */
+const DMAMap *iova_tree_find_iova(const IOVATree *tree, const DMAMap *map);
+
+/**
  * iova_tree_find_address:
  *
  * @tree: the iova tree to search from