qemu: Don't request nested entries in qemuBlockGetNamedNodeData

Use the 'flat' flag for 'query-named-block-nodes' if qemu supports
QEMU_CAPS_QMP_QUERY_NAMED_BLOCK_NODES_FLAT in qemuBlockGetNamedNodeData.

We don't need the data so plumb in whether qemu supports the
'flat' output.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_block.c

@@ -2768,11 +2768,13 @@ qemuBlockGetNamedNodeData(virDomainObjPtr vm,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     virQEMUDriverPtr driver = priv->driver;
     g_autoptr(virHashTable) blockNamedNodeData = NULL;
+    bool supports_flat = virQEMUCapsGet(priv->qemuCaps,
+                                        QEMU_CAPS_QMP_QUERY_NAMED_BLOCK_NODES_FLAT);
 
     if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
         return NULL;
 
-    blockNamedNodeData = qemuMonitorBlockGetNamedNodeData(priv->mon);
+    blockNamedNodeData = qemuMonitorBlockGetNamedNodeData(priv->mon, supports_flat);
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0 || !blockNamedNodeData)
         return NULL;

src/qemu/qemu_monitor.c

@@ -2199,17 +2199,20 @@ qemuMonitorBlockStatsUpdateCapacityBlockdev(qemuMonitorPtr mon,
 /**
  * qemuMonitorBlockGetNamedNodeData:
  * @mon: monitor object
+ * @supports_flat: don't query data for backing store
  *
  * Uses 'query-named-block-nodes' to retrieve information about individual
  * storage nodes and returns them in a hash table of qemuBlockNamedNodeDataPtrs
  * filled with the data. The hash table keys are node names.
  */
 virHashTablePtr
-qemuMonitorBlockGetNamedNodeData(qemuMonitorPtr mon)
+qemuMonitorBlockGetNamedNodeData(qemuMonitorPtr mon,
+                                 bool supports_flat)
 {
     QEMU_CHECK_MONITOR_NULL(mon);
+    VIR_DEBUG("supports_flat=%d", supports_flat);
 
-    return qemuMonitorJSONBlockGetNamedNodeData(mon);
+    return qemuMonitorJSONBlockGetNamedNodeData(mon, supports_flat);
 }
 
 

src/qemu/qemu_monitor.h

@@ -698,7 +698,8 @@ struct _qemuBlockNamedNodeData {
 };
 
 virHashTablePtr
-qemuMonitorBlockGetNamedNodeData(qemuMonitorPtr mon);
+qemuMonitorBlockGetNamedNodeData(qemuMonitorPtr mon,
+                                 bool supports_flat);
 
 int qemuMonitorBlockResize(qemuMonitorPtr mon,
                            const char *device,

src/qemu/qemu_monitor_json.c

@@ -3014,11 +3014,12 @@ qemuMonitorJSONBlockGetNamedNodeDataJSON(virJSONValuePtr nodes)
 
 
 virHashTablePtr
-qemuMonitorJSONBlockGetNamedNodeData(qemuMonitorPtr mon)
+qemuMonitorJSONBlockGetNamedNodeData(qemuMonitorPtr mon,
+                                     bool supports_flat)
 {
     g_autoptr(virJSONValue) nodes = NULL;
 
-    if (!(nodes = qemuMonitorJSONQueryNamedBlockNodes(mon, false)))
+    if (!(nodes = qemuMonitorJSONQueryNamedBlockNodes(mon, supports_flat)))
         return NULL;
 
     return qemuMonitorJSONBlockGetNamedNodeDataJSON(nodes);

src/qemu/qemu_monitor_json.h

@@ -91,7 +91,8 @@ virHashTablePtr
 qemuMonitorJSONBlockGetNamedNodeDataJSON(virJSONValuePtr nodes);
 
 virHashTablePtr
-qemuMonitorJSONBlockGetNamedNodeData(qemuMonitorPtr mon);
+qemuMonitorJSONBlockGetNamedNodeData(qemuMonitorPtr mon,
+                                     bool supports_flat);
 
 int qemuMonitorJSONBlockResize(qemuMonitorPtr mon,
                                const char *device,