@@ -1235,6 +1235,11 @@ static bool migrate_caps_check(bool *cap_list,
error_setg(errp, "Postcopy is not compatible with ignore-shared");
return false;
}
+
+ if (cap_list[MIGRATION_CAPABILITY_MULTIFD]) {
+ error_setg(errp, "Multifd is not supported in postcopy");
+ return false;
+ }
}
if (cap_list[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) {
@@ -1278,6 +1283,13 @@ 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;
}
@@ -2627,6 +2639,15 @@ 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
@@ -4237,6 +4258,8 @@ 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),
@@ -394,6 +394,7 @@ 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,
@@ -463,6 +463,12 @@
# procedure starts. The VM RAM is saved with running VM.
# (since 6.0)
#
+# @postcopy-preempt: If enabled, the migration process will allow postcopy
+# requests to preempt precopy stream, so postcopy requests
+# will be handled faster. This is a performance feature and
+# should not affect the correctness of postcopy migration.
+# (since 7.0)
+#
# Features:
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
#
@@ -476,7 +482,7 @@
'block', 'return-path', 'pause-before-switchover', 'multifd',
'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',
{ 'name': 'x-ignore-shared', 'features': [ 'unstable' ] },
- 'validate-uuid', 'background-snapshot'] }
+ 'validate-uuid', 'background-snapshot', 'postcopy-preempt'] }
##
# @MigrationCapabilityStatus: