Index: src/xen_internal.c
===================================================================
RCS file: /data/cvs/libxen/src/xen_internal.c,v
retrieving revision 1.96
diff -u -p -r1.96 xen_internal.c
--- src/xen_internal.c	29 Sep 2007 18:37:47 -0000	1.96
+++ src/xen_internal.c	22 Oct 2007 15:01:56 -0000
@@ -3035,24 +3035,27 @@ xenHypervisorNodeGetCellsFreeMemory(virC
     xen_op_v2_sys op_sys;
     int i, j, ret;
     xenUnifiedPrivatePtr priv;
-    static int nbNodeCells = -1;
-    virNodeInfo nodeInfo;
+    int nbNodeCells;
     
+    if (conn == NULL) {
+        virXenErrorFunc (VIR_ERR_INVALID_ARG, __FUNCTION__,
+                        "invalid argument", 0);
+        return -1;
+    }
 
-    if (nbNodeCells == -1) {
-        if (xenDaemonNodeGetInfo(conn, &nodeInfo)) {
-            virXenErrorFunc (VIR_ERR_XEN_CALL, __FUNCTION__,
-                             "cannot determine actual number of cells",0);
-            return -1;
-        }
-        nbNodeCells = nodeInfo.nodes;
+    nbNodeCells = xenNbCells(conn);
+    if (nbNodeCells < 0) {
+	virXenErrorFunc (VIR_ERR_XEN_CALL, __FUNCTION__,
+			 "cannot determine actual number of cells",0);
+	return(-1);
     }
 
-    if ((conn == NULL) || (maxCells < 1) || (startCell >= nbNodeCells)) {
+    if ((maxCells < 1) || (startCell >= nbNodeCells)) {
         virXenErrorFunc (VIR_ERR_INVALID_ARG, __FUNCTION__,
                         "invalid argument", 0);
         return -1;
     }
+
     /*
      * Support only sys_interface_version >=4
      */
Index: src/xen_unified.c
===================================================================
RCS file: /data/cvs/libxen/src/xen_unified.c,v
retrieving revision 1.24
diff -u -p -r1.24 xen_unified.c
--- src/xen_unified.c	15 Oct 2007 21:38:56 -0000	1.24
+++ src/xen_unified.c	22 Oct 2007 15:01:56 -0000
@@ -37,6 +37,9 @@
 #include "xs_internal.h"
 #include "xm_internal.h"
 
+static int
+xenUnifiedNodeGetInfo (virConnectPtr conn, virNodeInfoPtr info);
+
 /* The five Xen drivers below us. */
 static struct xenUnifiedDriver *drivers[XEN_UNIFIED_NR_DRIVERS] = {
     [XEN_UNIFIED_HYPERVISOR_OFFSET] = &xenHypervisorDriver,
@@ -64,6 +67,62 @@ xenUnifiedError (virConnectPtr conn, vir
                      errmsg, info, NULL, 0, 0, errmsg, info);
 }
 
+/*
+ * Helper functions currently used in the NUMA code
+ * Those variables should not be accessed directly but through helper 
+ * functions xenNbCells() and xenNbCpu() available to all Xen backends 
+ */
+static int nbNodeCells = -1;
+static int nbNodeCpus = -1;
+
+/**
+ * xenNumaInit:
+ * @conn: pointer to the hypervisor connection
+ *
+ * Initializer for previous variables. We currently assume that
+ * the number of physical CPU and the numebr of NUMA cell is fixed
+ * until reboot which might be false in future Xen implementations.
+ */
+static void
+xenNumaInit(virConnectPtr conn) {
+    virNodeInfo nodeInfo;
+    int ret;
+
+    ret = xenUnifiedNodeGetInfo(conn, &nodeInfo);
+    if (ret < 0)
+        return;
+    nbNodeCells = nodeInfo.nodes;
+    nbNodeCpus = nodeInfo.cpus;
+}
+
+/**
+ * xenNbCells:
+ * @conn: pointer to the hypervisor connection
+ *
+ * Number of NUMa cells present in the actual Node
+ *
+ * Returns the number of NUMA cells available on that Node
+ */
+int xenNbCells(virConnectPtr conn) {
+    if (nbNodeCells < 0)
+        xenNumaInit(conn);
+    return(nbNodeCells);
+}
+
+/**
+ * xenNbCpus:
+ * @conn: pointer to the hypervisor connection
+ *
+ * Number of NUMa cells present in the actual Node
+ *
+ * Returns the number of NUMA cells available on that Node
+ */
+int xenNbCpus(virConnectPtr conn) {
+    if (nbNodeCpus < 0)
+        xenNumaInit(conn);
+    return(nbNodeCpus);
+}
+
 /*----- Dispatch functions. -----*/
 
 /* These dispatch functions follow the model used historically
Index: src/xen_unified.h
===================================================================
RCS file: /data/cvs/libxen/src/xen_unified.h,v
retrieving revision 1.5
diff -u -p -r1.5 xen_unified.h
--- src/xen_unified.h	6 Jul 2007 15:11:22 -0000	1.5
+++ src/xen_unified.h	22 Oct 2007 15:01:56 -0000
@@ -116,6 +116,9 @@ struct _xenUnifiedPrivate {
 
 typedef struct _xenUnifiedPrivate *xenUnifiedPrivatePtr;
 
+
+int xenNbCells(virConnectPtr conn);
+int xenNbCpus(virConnectPtr conn);
 #ifdef __cplusplus
 }
 #endif