qemu: Enable migration events on QMP monitor

Even if QEMU supports migration events it doesn't send them by default.
We have to enable them by calling migrate-set-capabilities. Let's enable
migration events everytime we can and clear QEMU_CAPS_MIGRATION_EVENT in
case migrate-set-capabilities does not support events.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_monitor.c

@@ -163,7 +163,7 @@ VIR_ENUM_IMPL(qemuMonitorMigrationStatus,
 
 VIR_ENUM_IMPL(qemuMonitorMigrationCaps,
               QEMU_MONITOR_MIGRATION_CAPS_LAST,
-              "xbzrle", "auto-converge", "rdma-pin-all")
+              "xbzrle", "auto-converge", "rdma-pin-all", "events")
 
 VIR_ENUM_IMPL(qemuMonitorVMStatus,
               QEMU_MONITOR_VM_STATUS_LAST,

src/qemu/qemu_monitor.h

@@ -512,6 +512,7 @@ typedef enum {
     QEMU_MONITOR_MIGRATION_CAPS_XBZRLE,
     QEMU_MONITOR_MIGRATION_CAPS_AUTO_CONVERGE,
     QEMU_MONITOR_MIGRATION_CAPS_RDMA_PIN_ALL,
+    QEMU_MONITOR_MIGRATION_CAPS_EVENTS,
 
     QEMU_MONITOR_MIGRATION_CAPS_LAST
 } qemuMonitorMigrationCaps;

src/qemu/qemu_process.c

@@ -1548,7 +1548,7 @@ qemuConnectMonitor(virQEMUDriverPtr driver, virDomainObjPtr vm, int asyncJob,
                                                vm->def) < 0) {
         VIR_ERROR(_("Failed to set security context for monitor for %s"),
                   vm->def->name);
-        goto error;
+        return -1;
     }
 
     /* Hold an extra reference because we can't allow 'vm' to be
@@ -1580,26 +1580,38 @@ qemuConnectMonitor(virQEMUDriverPtr driver, virDomainObjPtr vm, int asyncJob,
     if (virSecurityManagerClearSocketLabel(driver->securityManager, vm->def) < 0) {
         VIR_ERROR(_("Failed to clear security context for monitor for %s"),
                   vm->def->name);
-        goto error;
+        return -1;
     }
 
     if (priv->mon == NULL) {
         VIR_INFO("Failed to connect monitor for %s", vm->def->name);
-        goto error;
+        return -1;
     }
 
 
     if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
-        goto error;
-    ret = qemuMonitorSetCapabilities(priv->mon);
-    if (ret == 0 &&
-        virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MONITOR_JSON))
-        ret = virQEMUCapsProbeQMP(priv->qemuCaps, priv->mon);
-    if (qemuDomainObjExitMonitor(driver, vm) < 0)
         return -1;
 
- error:
+    if (qemuMonitorSetCapabilities(priv->mon) < 0)
+        goto cleanup;
 
+    if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MONITOR_JSON) &&
+        virQEMUCapsProbeQMP(priv->qemuCaps, priv->mon) < 0)
+        goto cleanup;
+
+    if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATION_EVENT) &&
+        qemuMonitorSetMigrationCapability(priv->mon,
+                                          QEMU_MONITOR_MIGRATION_CAPS_EVENTS,
+                                          true) < 0) {
+        VIR_DEBUG("Cannot enable migration events; clearing capability");
+        virQEMUCapsClear(priv->qemuCaps, QEMU_CAPS_MIGRATION_EVENT);
+    }
+
+    ret = 0;
+
+ cleanup:
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
     return ret;
 }