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>

1 files changed, 21 insertions, 11 deletions

diff --git a/softmmu/memory.c b/softmmu/memory.c
index e5826fa..f2ac0d2 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -39,7 +39,7 @@
 static unsigned memory_region_transaction_depth;
 static bool memory_region_update_pending;
 static bool ioeventfd_update_pending;
-bool global_dirty_log;
+unsigned int global_dirty_tracking;
 
 static QTAILQ_HEAD(, MemoryListener) memory_listeners
     = QTAILQ_HEAD_INITIALIZER(memory_listeners);
@@ -1821,7 +1821,7 @@ uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
     uint8_t mask = mr->dirty_log_mask;
     RAMBlock *rb = mr->ram_block;
 
-    if (global_dirty_log && ((rb && qemu_ram_is_migratable(rb)) ||
+    if (global_dirty_tracking && ((rb && qemu_ram_is_migratable(rb)) ||
                              memory_region_is_iommu(mr))) {
         mask |= (1 << DIRTY_MEMORY_MIGRATION);
     }
@@ -2760,14 +2760,18 @@ void memory_global_after_dirty_log_sync(void)
 
 static VMChangeStateEntry *vmstate_change;
 
-void memory_global_dirty_log_start(void)
+void memory_global_dirty_log_start(unsigned int flags)
 {
     if (vmstate_change) {
         qemu_del_vm_change_state_handler(vmstate_change);
         vmstate_change = NULL;
     }
 
-    global_dirty_log = true;
+    assert(flags && !(flags & (~GLOBAL_DIRTY_MASK)));
+    assert(!(global_dirty_tracking & flags));
+    global_dirty_tracking |= flags;
+
+    trace_global_dirty_changed(global_dirty_tracking);
 
     MEMORY_LISTENER_CALL_GLOBAL(log_global_start, Forward);
 
@@ -2777,9 +2781,13 @@ void memory_global_dirty_log_start(void)
     memory_region_transaction_commit();
 }
 
-static void memory_global_dirty_log_do_stop(void)
+static void memory_global_dirty_log_do_stop(unsigned int flags)
 {
-    global_dirty_log = false;
+    assert(flags && !(flags & (~GLOBAL_DIRTY_MASK)));
+    assert((global_dirty_tracking & flags) == flags);
+    global_dirty_tracking &= ~flags;
+
+    trace_global_dirty_changed(global_dirty_tracking);
 
     /* Refresh DIRTY_MEMORY_MIGRATION bit.  */
     memory_region_transaction_begin();
@@ -2792,8 +2800,9 @@ static void memory_global_dirty_log_do_stop(void)
 static void memory_vm_change_state_handler(void *opaque, bool running,
                                            RunState state)
 {
+    unsigned int flags = (unsigned int)(uintptr_t)opaque;
     if (running) {
-        memory_global_dirty_log_do_stop();
+        memory_global_dirty_log_do_stop(flags);
 
         if (vmstate_change) {
             qemu_del_vm_change_state_handler(vmstate_change);
@@ -2802,18 +2811,19 @@ static void memory_vm_change_state_handler(void *opaque, bool running,
     }
 }
 
-void memory_global_dirty_log_stop(void)
+void memory_global_dirty_log_stop(unsigned int flags)
 {
     if (!runstate_is_running()) {
         if (vmstate_change) {
             return;
         }
         vmstate_change = qemu_add_vm_change_state_handler(
-                                memory_vm_change_state_handler, NULL);
+                                memory_vm_change_state_handler,
+                                (void *)(uintptr_t)flags);
         return;
     }
 
-    memory_global_dirty_log_do_stop();
+    memory_global_dirty_log_do_stop(flags);
 }
 
 static void listener_add_address_space(MemoryListener *listener,
@@ -2825,7 +2835,7 @@ static void listener_add_address_space(MemoryListener *listener,
     if (listener->begin) {
         listener->begin(listener);
     }
-    if (global_dirty_log) {
+    if (global_dirty_tracking) {
         if (listener->log_global_start) {
             listener->log_global_start(listener);
         }