migration: move some code to ram_save_host_page

Move some code from ram_save_target_page() to ram_save_host_page()
to make it be more readable for latter patches that dramatically
clean ram_save_target_page() up

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180330075128.26919-7-xiaoguangrong@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 19 insertions, 24 deletions

diff --git a/migration/ram.c b/migration/ram.c
index 79c7958993..c3628b020e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1483,38 +1483,23 @@ err:
  * Returns the number of pages written
  *
  * @rs: current RAM state
- * @ms: current migration state
  * @pss: data about the page we want to send
  * @last_stage: if we are at the completion stage
  */
 static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
                                 bool last_stage)
 {
-    int res = 0;
-
-    /* Check the pages is dirty and if it is send it */
-    if (migration_bitmap_clear_dirty(rs, pss->block, pss->page)) {
-        /*
-         * If xbzrle is on, stop using the data compression after first
-         * round of migration even if compression is enabled. In theory,
-         * xbzrle can do better than compression.
-         */
-        if (migrate_use_compression() &&
-            (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
-            res = ram_save_compressed_page(rs, pss, last_stage);
-        } else {
-            res = ram_save_page(rs, pss, last_stage);
-        }
-
-        if (res < 0) {
-            return res;
-        }
-        if (pss->block->unsentmap) {
-            clear_bit(pss->page, pss->block->unsentmap);
-        }
+    /*
+     * If xbzrle is on, stop using the data compression after first
+     * round of migration even if compression is enabled. In theory,
+     * xbzrle can do better than compression.
+     */
+    if (migrate_use_compression() &&
+        (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
+        return ram_save_compressed_page(rs, pss, last_stage);
     }
 
-    return res;
+    return ram_save_page(rs, pss, last_stage);
 }
 
 /**
@@ -1543,12 +1528,22 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
         qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS;
 
     do {
+        /* Check the pages is dirty and if it is send it */
+        if (!migration_bitmap_clear_dirty(rs, pss->block, pss->page)) {
+            pss->page++;
+            continue;
+        }
+
         tmppages = ram_save_target_page(rs, pss, last_stage);
         if (tmppages < 0) {
             return tmppages;
         }
 
         pages += tmppages;
+        if (pss->block->unsentmap) {
+            clear_bit(pss->page, pss->block->unsentmap);
+        }
+
         pss->page++;
     } while ((pss->page & (pagesize_bits - 1)) &&
              offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS));