Re: [libvirt PATCH v2 2/5] qemu_monitor_json: Add qemuMonitorJSONGetMigrationBlockers
On Wed, Jul 20, 2022 at 11:11:51 +0200, Eugenio Pérez wrote:
This will allow qemuMigrationSrcIsAllowed to dynamically ask for
migration blockers, reducing duplication.
Signed-off-by: Eugenio Pérez <eperezma(a)redhat.com>
---
src/qemu/qemu_monitor_json.c | 35 +++++++++++++++++++++++++++++++++++
src/qemu/qemu_monitor_json.h | 3 +++
2 files changed, 38 insertions(+)
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 5e4a86e5ad..a53d721720 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -3338,6 +3338,41 @@ int qemuMonitorJSONMigrate(qemuMonitor *mon,
return 0;
}
+int qemuMonitorJSONGetMigrationBlockers(qemuMonitor *mon,
+ char ***blockers)
+{
+ g_autoptr(virJSONValue) cmd = NULL;
+ g_autoptr(virJSONValue) reply = NULL;
+ virJSONValue *data;
+ virJSONValue *jblockers;
+ size_t i;
+
+ if (!(cmd = qemuMonitorJSONMakeCommand("query-migrate", NULL)))
+ return -1;
We already have a function which calls query-migrate in JSON monitor,
but I actually agree with adding this separate function as it serves a
completely different purpose.
+
+ if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
+ return -1;
+
+ if (qemuMonitorJSONCheckReply(cmd, reply, VIR_JSON_TYPE_OBJECT) < 0)
+ return -1;
+
+ data = virJSONValueObjectGetObject(reply, "return");
+
+ if (!(jblockers = virJSONValueObjectGetArray(data, "blocked-reasons")))
+ return -1;
This is not an error (not to mention that you would return -1 without a
proper error message) as missing blocked-reasons means there's no
migration blocker and the domain can be migrated (as long as the
QEMU_CAPS_MIGRATION_BLOCKED_REASONS capability is set).
I think we should return 0 and set *blockers = NULL in this case.
+
+ /* NULL terminated array */
This comment would be better as part of a proper documentation above the
function.
+ *blockers = g_new0(char *, virJSONValueArraySize(jblockers) +
1);
+ for (i = 0; i < virJSONValueArraySize(jblockers); i++) {
+ virJSONValue *jblocker = virJSONValueArrayGet(jblockers, i);
+ const char *blocker = virJSONValueGetString(jblocker);
+
+ (*blockers)[i] = g_strdup(blocker);
+ }
+
+ return 0;
+}
+
int qemuMonitorJSONMigrateCancel(qemuMonitor *mon)
{
g_autoptr(virJSONValue) cmd = qemuMonitorJSONMakeCommand("migrate_cancel",
NULL);
Jirka