From 096631bd95ac8f873fed9f62c4a57076ffcdb54d Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 13 Jun 2016 12:16:45 +0100 Subject: 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 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 --- migration/migration.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/migration/migration.c b/migration/migration.c index 7bc406a870..253395c3c2 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -720,6 +720,7 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, { 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 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 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; + } } } -- cgit v1.2.3