[RFC v2 11/26] memory: Rename address_space_lookup_region and expose it to Rust

address_space_lookup_region() returns a pointer to a
MemoryRegionSection instead of a MemoryRegion. Therefore, rename
it to address_space_lookup_section().

Add its declaration to memory.h so that bindgen can generate
bindings for it.

This interface will be used to implement GuestMemory::find_region()
in the vm_memory crate.

In addition, add its documentation in memory.h.

Signed-off-by: Zhao Liu <[email protected]>
---
 include/system/memory.h | 21 +++++++++++++++++++++
 system/physmem.c        |  8 ++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index bf5bfa7164fb..c32e3d01f825 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -948,6 +948,27 @@ static inline FlatView *address_space_to_flatview(const AddressSpace *as)
     return qatomic_rcu_read(&as->current_map);
 }
 
+/**
+ * address_space_lookup_section: Find the MemoryRegionSection within a
+ * given #AddressSpaceDispatch.
+ *
+ * @d: The AddressSpaceDispatch to search within.
+ * @addr: The address to look up.
+ * @resolve_subpage: If 'true', resolve to a subpage section if the
+ * region is a subpage container.
+ *
+ * This function translates an address (@addr) into its corresponding
+ * #MemoryRegionSection within a given address space dispatch (@d).
+ * Must be called within an RCU critical section.
+ *
+ * Returns:
+ * A pointer to the #MemoryRegionSection. If the address is not
+ * mapped, this will be a pointer to the 'unassigned' section.
+ */
+MemoryRegionSection *address_space_lookup_section(AddressSpaceDispatch *d,
+                                                  hwaddr addr,
+                                                  bool resolve_subpage);
+
 /**
  * flatview_ref: Atomically increment the reference count of a #FlatView.
  *
diff --git a/system/physmem.c b/system/physmem.c
index c21ea929153e..f807e60aa348 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -342,9 +342,9 @@ static MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d, hwaddr addr)
 }
 
 /* Called from RCU critical section */
-static MemoryRegionSection *address_space_lookup_region(AddressSpaceDispatch *d,
-                                                        hwaddr addr,
-                                                        bool resolve_subpage)
+MemoryRegionSection *address_space_lookup_section(AddressSpaceDispatch *d,
+                                                  hwaddr addr,
+                                                  bool resolve_subpage)
 {
     MemoryRegionSection *section = qatomic_read(&d->mru_section);
     subpage_t *subpage;
@@ -370,7 +370,7 @@ address_space_translate_internal(AddressSpaceDispatch *d, hwaddr addr, hwaddr *x
     MemoryRegion *mr;
     Int128 diff;
 
-    section = address_space_lookup_region(d, addr, resolve_subpage);
+    section = address_space_lookup_section(d, addr, resolve_subpage);
     /* Compute offset within MemoryRegionSection */
     addr -= section->offset_within_address_space;
 
-- 
2.34.1