memory: make global_dirty_tracking a bitmask

since dirty ring has been introduced, there are two methods
to track dirty pages of vm. it seems that "logging" has
a hint on the method, so rename the global_dirty_log to
global_dirty_tracking would make description more accurate.

dirty rate measurement may start or stop dirty tracking during
calculation. this conflict with migration because stop dirty
tracking make migration leave dirty pages out then that'll be
a problem.

make global_dirty_tracking a bitmask can let both migration and
dirty rate measurement work fine. introduce GLOBAL_DIRTY_MIGRATION
and GLOBAL_DIRTY_DIRTY_RATE to distinguish what current dirty
tracking aims for, migration or dirty rate.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <9c9388657cfa0301bd2c1cfa36e7cf6da4aeca19.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

2 files changed, 19 insertions, 5 deletions

diff --git a/include/exec/memory.h b/include/exec/memory.h
index a185b6d..0428045 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -61,7 +61,17 @@ static inline void fuzz_dma_read_cb(size_t addr,
 }
 #endif
 
-extern bool global_dirty_log;
+/* Possible bits for global_dirty_log_{start|stop} */
+
+/* Dirty tracking enabled because migration is running */
+#define GLOBAL_DIRTY_MIGRATION  (1U << 0)
+
+/* Dirty tracking enabled because measuring dirty rate */
+#define GLOBAL_DIRTY_DIRTY_RATE (1U << 1)
+
+#define GLOBAL_DIRTY_MASK  (0x3)
+
+extern unsigned int global_dirty_tracking;
 
 typedef struct MemoryRegionOps MemoryRegionOps;
 
@@ -2388,13 +2398,17 @@ void memory_listener_unregister(MemoryListener *listener);
 
 /**
  * memory_global_dirty_log_start: begin dirty logging for all regions
+ *
+ * @flags: purpose of starting dirty log, migration or dirty rate
  */
-void memory_global_dirty_log_start(void);
+void memory_global_dirty_log_start(unsigned int flags);
 
 /**
  * memory_global_dirty_log_stop: end dirty logging for all regions
+ *
+ * @flags: purpose of stopping dirty log, migration or dirty rate
  */
-void memory_global_dirty_log_stop(void);
+void memory_global_dirty_log_stop(unsigned int flags);
 
 void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled);
 
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 551876b..45c9132 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -369,7 +369,7 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
 
                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
 
-                    if (global_dirty_log) {
+                    if (global_dirty_tracking) {
                         qatomic_or(
                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
                                 temp);
@@ -392,7 +392,7 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
     } else {
         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
 
-        if (!global_dirty_log) {
+        if (!global_dirty_tracking) {
             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
         }