[PULL 10/10] migration: block incoming colo when capability is disabled

[Juan Quintela <quintela@redhat.com>]

From: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

We generally require same set of capabilities on source and target.
Let's require x-colo capability to use COLO on target.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Message-Id: <20230428194928.1426370-11-vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 docs/COLO-FT.txt      | 1 +
 migration/migration.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt
index 8ec653f81c..2e760a4aee 100644
--- a/docs/COLO-FT.txt
+++ b/docs/COLO-FT.txt
@@ -210,6 +210,7 @@ children.0=childs0 \
 
 3. On Secondary VM's QEMU monitor, issue command
 {"execute":"qmp_capabilities"}
+{"execute": "migrate-set-capabilities", "arguments": {"capabilities": [ {"capability": "x-colo", "state": true } ] } }
 {"execute": "nbd-server-start", "arguments": {"addr": {"type": "inet", "data": {"host": "0.0.0.0", "port": "9999"} } } }
 {"execute": "nbd-server-add", "arguments": {"device": "parent0", "writable": true } }
 
diff --git a/migration/migration.c b/migration/migration.c
index 4959f7ee44..7558c8edbd 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -398,6 +398,12 @@ int migration_incoming_enable_colo(void)
     return -ENOTSUP;
 #endif
 
+    if (!migrate_colo()) {
+        error_report("ENABLE_COLO command come in migration stream, but c-colo "
+                     "capability is not set");
+        return -EINVAL;
+    }
+
     if (ram_block_discard_disable(true)) {
         error_report("COLO: cannot disable RAM discard");
         return -EBUSY;
-- 
2.40.0