[Libvir] Small cleanup patch for Xen NUMA

[Daniel Veillard]

  xenHypervisorNodeGetCellsFreeMemory was calling xend to find the 
number of cells on a node and keeping the information thereafter in
a static variable. This patch just move the lookup code in the xen_unified
driver, using the unified call (and hence the hypervisor instead of
xend rpc). Provides the same for CPUs. Also helps centralizing those
lookup in case Xen supports dynamic CPUs or cells in the future.

Daniel

-- 
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard      | virtualization library  http://libvirt.org/
veillard at redhat.com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine  http://rpmfind.net/
-------------- next part --------------
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