2 files changed, 19 insertions, 0 deletions
diff --git a/migration/migration.c b/migration/migration.c
index 78f5057373..ce7bb68cdc 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1297,6 +1297,13 @@ static bool migrate_caps_check(bool *cap_list,
         return false;
     }
 
+    if (cap_list[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT]) {
+        if (!cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM]) {
+            error_setg(errp, "Postcopy preempt requires postcopy-ram");
+            return false;
+        }
+    }
+
     return true;
 }
 
@@ -2663,6 +2670,15 @@ bool migrate_background_snapshot(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT];
 }
 
+bool migrate_postcopy_preempt(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT];
+}
+
 /* migration thread support */
 /*
  * Something bad happened to the RP stream, mark an error
@@ -4274,6 +4290,8 @@ static Property migration_properties[] = {
     DEFINE_PROP_MIG_CAP("x-compress", MIGRATION_CAPABILITY_COMPRESS),
     DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS),
     DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM),
+    DEFINE_PROP_MIG_CAP("x-postcopy-preempt",
+                        MIGRATION_CAPABILITY_POSTCOPY_PREEMPT),
     DEFINE_PROP_MIG_CAP("x-colo", MIGRATION_CAPABILITY_X_COLO),
     DEFINE_PROP_MIG_CAP("x-release-ram", MIGRATION_CAPABILITY_RELEASE_RAM),
     DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
diff --git a/migration/migration.h b/migration/migration.h
index 485d58b95f..d2269c826c 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -400,6 +400,7 @@ int migrate_decompress_threads(void);
 bool migrate_use_events(void);
 bool migrate_postcopy_blocktime(void);
 bool migrate_background_snapshot(void);
+bool migrate_postcopy_preempt(void);
 
 /* Sending on the return path - generic and then for each message type */
 void migrate_send_rp_shut(MigrationIncomingState *mis,