util: Introduce virResctrlAllocSetMemoryBandwidth

Introduce an API to allow setting of the MBA from domain XML.

Signed-off-by: Bing Niu <bing.niu@intel.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>

src/libvirt_private.syms

@@ -2656,6 +2656,7 @@ virResctrlAllocNew;
 virResctrlAllocRemove;
 virResctrlAllocSetCacheSize;
 virResctrlAllocSetID;
+virResctrlAllocSetMemoryBandwidth;
 virResctrlInfoGetCache;
 virResctrlInfoNew;
 

src/util/virresctrl.c

@@ -965,6 +965,54 @@ virResctrlAllocForeachCache(virResctrlAllocPtr alloc,
 }
 
 
+/* virResctrlAllocSetMemoryBandwidth
+ * @alloc: Pointer to an active allocation
+ * @id: node id of MBA to be set
+ * @memory_bandwidth: new memory bandwidth value
+ *
+ * Set the @memory_bandwidth for the node @id entry in the @alloc.
+ *
+ * Returns 0 on success, -1 on failure with error message set.
+ */
+int
+virResctrlAllocSetMemoryBandwidth(virResctrlAllocPtr alloc,
+                                  unsigned int id,
+                                  unsigned int memory_bandwidth)
+{
+    virResctrlAllocMemBWPtr mem_bw = alloc->mem_bw;
+
+    if (memory_bandwidth > 100) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("Memory Bandwidth value exceeding 100 is invalid."));
+        return -1;
+    }
+
+    if (!mem_bw) {
+        if (VIR_ALLOC(mem_bw) < 0)
+            return -1;
+        alloc->mem_bw = mem_bw;
+    }
+
+    if (mem_bw->nbandwidths <= id &&
+        VIR_EXPAND_N(mem_bw->bandwidths, mem_bw->nbandwidths,
+                     id - mem_bw->nbandwidths + 1) < 0)
+        return -1;
+
+    if (mem_bw->bandwidths[id]) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Memory Bandwidth already defined for node %u"),
+                       id);
+        return -1;
+    }
+
+    if (VIR_ALLOC(mem_bw->bandwidths[id]) < 0)
+        return -1;
+
+    *(mem_bw->bandwidths[id]) = memory_bandwidth;
+    return 0;
+}
+
+
 /* virResctrlAllocForeachMemory
  * @alloc: Pointer to an active allocation
  * @cb: Callback function

src/util/virresctrl.h

@@ -95,6 +95,11 @@ virResctrlAllocForeachCache(virResctrlAllocPtr alloc,
                             virResctrlAllocForeachCacheCallback cb,
                             void *opaque);
 
+int
+virResctrlAllocSetMemoryBandwidth(virResctrlAllocPtr alloc,
+                                  unsigned int id,
+                                  unsigned int memory_bandwidth);
+
 int
 virResctrlAllocForeachMemory(virResctrlAllocPtr resctrl,
                              virResctrlAllocForeachMemoryCallback cb,