Split ram_save_block

ram_save_block is getting a bit too complicated, and does two separate
things:
   1) Finds a page to send
   2) Sends the page (dealing with compression etc)

Split into 'ram_save_page' to send the page and deal with compression (2)
Rename remaining function to 'ram_find_and_save_block'

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

arch_init.c

@@ -560,45 +560,22 @@ static void migration_bitmap_sync(void)
 }
 
 /*
- * ram_save_block: Writes a page of memory to the stream f
+ * ram_save_page: Send the given page to the stream
  *
- * Returns:  The number of bytes written.
+ * Returns: Number of bytes written.
- *           0 means no dirty pages
  */
-
+static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
-static int ram_save_block(QEMUFile *f, bool last_stage)
+                         bool last_stage)
 {
-    RAMBlock *block = last_seen_block;
+    int bytes_sent;
-    ram_addr_t offset = last_offset;
+    int cont;
-    bool complete_round = false;
-    int bytes_sent = 0;
-    MemoryRegion *mr;
     ram_addr_t current_addr;
-
+    MemoryRegion *mr = block->mr;
-    if (!block)
-        block = QTAILQ_FIRST(&ram_list.blocks);
-
-    while (true) {
-        mr = block->mr;
-        offset = migration_bitmap_find_and_reset_dirty(mr, offset);
-        if (complete_round && block == last_seen_block &&
-            offset >= last_offset) {
-            break;
-        }
-        if (offset >= block->length) {
-            offset = 0;
-            block = QTAILQ_NEXT(block, next);
-            if (!block) {
-                block = QTAILQ_FIRST(&ram_list.blocks);
-                complete_round = true;
-                ram_bulk_stage = false;
-            }
-        } else {
-            int ret;
     uint8_t *p;
+    int ret;
     bool send_async = true;
-            int cont = (block == last_sent_block) ?
+
-                RAM_SAVE_FLAG_CONTINUE : 0;
+    cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0;
 
     p = memory_region_get_ram_ptr(mr) + offset;
 
@@ -652,6 +629,46 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
     }
 
     XBZRLE_cache_unlock();
+
+    return bytes_sent;
+}
+
+/*
+ * ram_find_and_save_block: Finds a page to send and sends it to f
+ *
+ * Returns:  The number of bytes written.
+ *           0 means no dirty pages
+ */
+
+static int ram_find_and_save_block(QEMUFile *f, bool last_stage)
+{
+    RAMBlock *block = last_seen_block;
+    ram_addr_t offset = last_offset;
+    bool complete_round = false;
+    int bytes_sent = 0;
+    MemoryRegion *mr;
+
+    if (!block)
+        block = QTAILQ_FIRST(&ram_list.blocks);
+
+    while (true) {
+        mr = block->mr;
+        offset = migration_bitmap_find_and_reset_dirty(mr, offset);
+        if (complete_round && block == last_seen_block &&
+            offset >= last_offset) {
+            break;
+        }
+        if (offset >= block->length) {
+            offset = 0;
+            block = QTAILQ_NEXT(block, next);
+            if (!block) {
+                block = QTAILQ_FIRST(&ram_list.blocks);
+                complete_round = true;
+                ram_bulk_stage = false;
+            }
+        } else {
+            bytes_sent = ram_save_page(f, block, offset, last_stage);
+
             /* if page is unmodified, continue to the next */
             if (bytes_sent > 0) {
                 last_sent_block = block;
@@ -850,7 +867,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
     while ((ret = qemu_file_rate_limit(f)) == 0) {
         int bytes_sent;
 
-        bytes_sent = ram_save_block(f, false);
+        bytes_sent = ram_find_and_save_block(f, false);
         /* no more blocks to sent */
         if (bytes_sent == 0) {
             break;
@@ -912,7 +929,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
     while (true) {
         int bytes_sent;
 
-        bytes_sent = ram_save_block(f, true);
+        bytes_sent = ram_find_and_save_block(f, true);
         /* no more blocks to sent */
         if (bytes_sent == 0) {
             break;