ram: Move xbzrle_cache_miss_prev into RAMState

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>

migration/ram.c

@@ -161,6 +161,8 @@ struct RAMState {
     uint64_t bytes_xfer_prev;
     /* number of dirty pages since start_time */
     uint64_t num_dirty_pages_period;
+    /* xbzrle misses since the beginning of the period */
+    uint64_t xbzrle_cache_miss_prev;
 };
 typedef struct RAMState RAMState;
 
@@ -624,7 +626,6 @@ static void migration_bitmap_sync_range(RAMState *rs, ram_addr_t start,
 }
 
 /* Fix me: there are too many global variables used in migration process. */
-static uint64_t xbzrle_cache_miss_prev;
 static uint64_t iterations_prev;
 
 static void migration_bitmap_sync_init(RAMState *rs)
@@ -632,7 +633,7 @@ static void migration_bitmap_sync_init(RAMState *rs)
     rs->time_last_bitmap_sync = 0;
     rs->bytes_xfer_prev = 0;
     rs->num_dirty_pages_period = 0;
-    xbzrle_cache_miss_prev = 0;
+    rs->xbzrle_cache_miss_prev = 0;
     iterations_prev = 0;
 }
 
@@ -714,11 +715,11 @@ static void migration_bitmap_sync(RAMState *rs)
             if (iterations_prev != acct_info.iterations) {
                 acct_info.xbzrle_cache_miss_rate =
                    (double)(acct_info.xbzrle_cache_miss -
-                            xbzrle_cache_miss_prev) /
+                            rs->xbzrle_cache_miss_prev) /
                    (acct_info.iterations - iterations_prev);
             }
             iterations_prev = acct_info.iterations;
-            xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
+            rs->xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
         }
         s->dirty_pages_rate = rs->num_dirty_pages_period * 1000
             / (end_time - rs->time_last_bitmap_sync);