Postcopy: Check for support when setting the capability
Knowing whether the destination host supports migration with
postcopy can be tricky.
The destination doesn't need the capability set, however
if we set it then use the opportunity to do the test and
tell the user/management layer early.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 1465816605-29488-7-git-send-email-dgilbert@redhat.com
Message-Id: <1465816605-29488-7-git-send-email-dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c
index 7bc406a..253395c 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -720,6 +720,7 @@
{
MigrationState *s = migrate_get_current();
MigrationCapabilityStatusList *cap;
+ bool old_postcopy_cap = migrate_postcopy_ram();
if (migration_is_setup_or_active(s->state)) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
@@ -742,6 +743,19 @@
s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] =
false;
}
+ /* This check is reasonably expensive, so only when it's being
+ * set the first time, also it's only the destination that needs
+ * special support.
+ */
+ if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
+ !postcopy_ram_supported_by_host()) {
+ /* postcopy_ram_supported_by_host will have emitted a more
+ * detailed message
+ */
+ error_report("Postcopy is not supported");
+ s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM] =
+ false;
+ }
}
}