migration: migration_thread_is_self

Define and export migration_thread_is_self to eliminate a dependency
on MigrationState.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-7-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

include/migration/misc.h

@@ -61,6 +61,7 @@ void migration_object_init(void);
 void migration_shutdown(void);
 bool migration_is_idle(void);
 bool migration_is_active(void);
+bool migration_thread_is_self(void);
 bool migration_is_setup_or_active(void);
 bool migrate_mode_is_cpr(MigrationState *);
 

migration/migration.c

@@ -1647,6 +1647,13 @@ bool migration_is_active(void)
             s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
 }
 
+bool migration_thread_is_self(void)
+{
+    MigrationState *s = current_migration;
+
+    return qemu_thread_is_self(&s->thread);
+}
+
 bool migrate_mode_is_cpr(MigrationState *s)
 {
     return s->parameters.mode == MIG_MODE_CPR_REBOOT;

system/dirtylimit.c

@@ -25,7 +25,6 @@
 #include "sysemu/kvm.h"
 #include "trace.h"
 #include "migration/misc.h"
-#include "migration/migration.h"
 
 /*
  * Dirtylimit stop working if dirty page rate error
@@ -448,10 +447,8 @@ static void dirtylimit_cleanup(void)
  */
 static bool dirtylimit_is_allowed(void)
 {
-    MigrationState *ms = migrate_get_current();
-
     if (migration_is_running() &&
-        (!qemu_thread_is_self(&ms->thread)) &&
+        !migration_thread_is_self() &&
         migrate_dirty_limit() &&
         dirtylimit_in_service()) {
         return false;