diff --git a/qemu/include/qemu/bitmap.h b/qemu/include/qemu/bitmap.h
index 80297364..1bae171d 100644
--- a/qemu/include/qemu/bitmap.h
+++ b/qemu/include/qemu/bitmap.h
@@ -48,6 +48,8 @@
 #define DECLARE_BITMAP(name,bits)                  \
         unsigned long name[BITS_TO_LONGS(bits)]
 
+long slow_bitmap_count_one(const unsigned long *bitmap, long nbits);
+
 static inline unsigned long *bitmap_try_new(long nbits)
 {
     long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
@@ -63,6 +65,15 @@ static inline unsigned long *bitmap_new(long nbits)
     return ptr;
 }
 
+static inline long bitmap_count_one(const unsigned long *bitmap, long nbits)
+{
+    if (small_nbits(nbits)) {
+        return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits));
+    } else {
+        return slow_bitmap_count_one(bitmap, nbits);
+    }
+}
+
 void bitmap_set(unsigned long *map, long i, long len);
 void bitmap_set_atomic(unsigned long *map, long i, long len);
 void bitmap_clear(unsigned long *map, long start, long nr);
diff --git a/qemu/util/bitmap.c b/qemu/util/bitmap.c
index 037eb0f0..d605244a 100644
--- a/qemu/util/bitmap.c
+++ b/qemu/util/bitmap.c
@@ -148,3 +148,18 @@ void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src,
         nr -= BITS_PER_LONG;
     }
 }
+
+long slow_bitmap_count_one(const unsigned long *bitmap, long nbits)
+{
+    long k, lim = nbits / BITS_PER_LONG, result = 0;
+
+    for (k = 0; k < lim; k++) {
+        result += ctpopl(bitmap[k]);
+    }
+
+    if (nbits % BITS_PER_LONG) {
+        result += ctpopl(bitmap[k] & BITMAP_LAST_WORD_MASK(nbits));
+    }
+
+    return result;
+}