conf: numa: Add helper to count total memory size configured in NUMA

The total NUMA memory consists of the sum of individual NUMA node memory
amounts.

src/conf/numa_conf.c

@@ -894,3 +894,16 @@ virDomainNumaSetNodeMemorySize(virDomainNumaPtr numa,
 {
     numa->mem_nodes[node].mem = size;
 }
+
+
+unsigned long long
+virDomainNumaGetMemorySize(virDomainNumaPtr numa)
+{
+    size_t i;
+    unsigned long long ret = 0;
+
+    for (i = 0; i < numa->nmem_nodes; i++)
+        ret += numa->mem_nodes[i].mem;
+
+    return ret;
+}

src/conf/numa_conf.h

@@ -95,6 +95,8 @@ virNumaMemAccess virDomainNumaGetNodeMemoryAccessMode(virDomainNumaPtr numa,
 unsigned long long virDomainNumaGetNodeMemorySize(virDomainNumaPtr numa,
                                                   size_t node)
     ATTRIBUTE_NONNULL(1);
+unsigned long long virDomainNumaGetMemorySize(virDomainNumaPtr numa)
+    ATTRIBUTE_NONNULL(1);
 
 /*
  * Formatters

src/libvirt_private.syms

@@ -630,6 +630,7 @@ virNodeDeviceObjUnlock;
 virDomainNumaCheckABIStability;
 virDomainNumaEquals;
 virDomainNumaFree;
+virDomainNumaGetMemorySize;
 virDomainNumaGetNodeCount;
 virDomainNumaGetNodeCpumask;
 virDomainNumaGetNodeMemoryAccessMode;