[PATCH V2] memory: flat section iterator

* [PATCH V2] memory: flat section iterator
@ 2023-02-07 19:03 Steve Sistare
  2023-02-07 20:10 ` Peter Xu
  0 siblings, 1 reply; 6+ messages in thread
From: Steve Sistare @ 2023-02-07 19:03 UTC (permalink / raw)
  To: qemu-devel
  Cc: Paolo Bonzini, David Hildenbrand, Marc-André Lureau,
	Peter Xu, Philippe Mathieu-Daudé,
	Alex Williamson, Steve Sistare

Add an iterator over the sections of a flattened address space.
This will be needed by cpr to issue vfio ioctl's on the same memory
ranges that are already programmed.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/exec/memory.h | 31 +++++++++++++++++++++++++++++++
 softmmu/memory.c      | 21 +++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 3224e09..b6ca3f5 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -2376,6 +2376,37 @@ void memory_region_set_ram_discard_manager(MemoryRegion *mr,
                                            RamDiscardManager *rdm);
 
 /**
+ * memory_region_section_cb: callback for address_space_flat_for_each_section()
+ *
+ * @mrs: MemoryRegionSection of the range
+ * @opaque: data pointer passed to address_space_flat_for_each_section()
+ * @errp: error message, returned to the address_space_flat_for_each_section
+ *        caller.
+ *
+ * Returns: non-zero to stop the iteration, and 0 to continue.  The same
+ * non-zero value is returned to the address_space_flat_for_each_section caller.
+ */
+
+typedef int (*memory_region_section_cb)(MemoryRegionSection *mrs,
+                                        void *opaque,
+                                        Error **errp);
+
+/**
+ * address_space_flat_for_each_section: walk the ranges in the address space
+ * flat view and call @func for each.  Return 0 on success, else return non-zero
+ * with a message in @errp.
+ *
+ * @as: target address space
+ * @func: callback function
+ * @opaque: passed to @func
+ * @errp: passed to @func
+ */
+int address_space_flat_for_each_section(AddressSpace *as,
+                                        memory_region_section_cb func,
+                                        void *opaque,
+                                        Error **errp);
+
+/**
  * memory_region_find: translate an address/size relative to a
  * MemoryRegion into a #MemoryRegionSection.
  *
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 9d64efc..57c3131 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -2748,6 +2748,27 @@ bool memory_region_is_mapped(MemoryRegion *mr)
     return !!mr->container || mr->mapped_via_alias;
 }
 
+int address_space_flat_for_each_section(AddressSpace *as,
+                                        memory_region_section_cb func,
+                                        void *opaque,
+                                        Error **errp)
+{
+    FlatView *view = address_space_get_flatview(as);
+    FlatRange *fr;
+    int ret;
+
+    FOR_EACH_FLAT_RANGE(fr, view) {
+        MemoryRegionSection mrs = section_from_flat_range(fr, view);
+        ret = func(&mrs, opaque, errp);
+        if (ret) {
+            return ret;
+        }
+    }
+
+    flatview_unref(view);
+    return 0;
+}
+
 /* Same as memory_region_find, but it does not add a reference to the
  * returned region.  It must be called from an RCU critical section.
  */
-- 
1.8.3.1



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