[PATCH 03 of 10 [RFC]] libxc, libxl: Introduce xc_nodemap_t and libxl_nodemap

[Dario Faggioli <raistlin@linux.it>]

Exactly as we have xc_cpumap_t, something similar for representing
NUMA nodes (i.e., xc_nodemap_t and nodemap_t) could be useful. The
same applies to libxl_cpumap, which on its turn now has its
node-related counterpart, libxl_nodemap.

This is all in preparation for making it possible explicit
specification of the `node affinity` of a guest.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>

diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -35,21 +35,49 @@ int xc_get_max_cpus(xc_interface *xch)
     return max_cpus;
 }
 
+int xc_get_max_nodes(xc_interface *xch)
+{
+    static int max_nodes = 0;
+    xc_physinfo_t physinfo;
+
+    if ( max_nodes )
+        return max_nodes;
+
+    if ( !xc_physinfo(xch, &physinfo) )
+        max_nodes = physinfo.max_node_id + 1;
+
+    return max_nodes;
+}
+
 int xc_get_cpumap_size(xc_interface *xch)
 {
     return (xc_get_max_cpus(xch) + 7) / 8;
 }
 
-xc_cpumap_t xc_cpumap_alloc(xc_interface *xch)
+int xc_get_nodemap_size(xc_interface *xch)
 {
-    int sz;
+    return (xc_get_max_nodes(xch) + 7) / 8;
+}
 
-    sz = xc_get_cpumap_size(xch);
+/* XXX See [*] below ... */
+static xc_cpumap_t __xc_map_alloc(xc_interface *xch, int sz)
+{
     if (sz == 0)
         return NULL;
     return calloc(1, sz);
 }
 
+xc_cpumap_t xc_cpumap_alloc(xc_interface *xch)
+{
+    return __xc_map_alloc(xch, xc_get_cpumap_size(xch));
+}
+
+xc_nodemap_t xc_nodemap_alloc(xc_interface *xch)
+{
+    /* XXX [*] How bad is this? Ideas? */
+    return (xc_nodemap_t) __xc_map_alloc(xch, xc_get_nodemap_size(xch));
+}
+
 int xc_readconsolering(xc_interface *xch,
                        char *buffer,
                        unsigned int *pnr_chars,
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -330,6 +330,20 @@ int xc_get_cpumap_size(xc_interface *xch
 xc_cpumap_t xc_cpumap_alloc(xc_interface *xch);
 
 /*
+ * NODEMAP handling
+ */
+typedef uint8_t *xc_nodemap_t;
+
+/* return maximum number of NUMA nodes the hypervisor supports */
+int xc_get_max_nodes(xc_interface *xch);
+
+/* return array size for nodemap */
+int xc_get_nodemap_size(xc_interface *xch);
+
+/* allocate a nodemap */
+xc_nodemap_t xc_nodemap_alloc(xc_interface *xch);
+
+/*
  * DOMAIN DEBUGGING FUNCTIONS
  */
 
diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -486,11 +486,27 @@ int libxl_cpumap_alloc(libxl_ctx *ctx, l
     return libxl_map_alloc(ctx, cpumap, max_cpus);
 }
 
+int libxl_nodemap_alloc(libxl_ctx *ctx, libxl_nodemap *nodemap)
+{
+    int max_nodes;
+
+    max_nodes = libxl_get_max_nodes(ctx);
+    if (max_nodes == 0)
+        return ERROR_FAIL;
+
+    return libxl_map_alloc(ctx, nodemap, max_nodes);
+}
+
 int libxl_get_max_cpus(libxl_ctx *ctx)
 {
     return xc_get_max_cpus(ctx->xch);
 }
 
+int libxl_get_max_nodes(libxl_ctx *ctx)
+{
+    return xc_get_max_nodes(ctx->xch);
+}
+
 int libxl__enum_from_string(const libxl_enum_string_table *t,
                             const char *s, int *e)
 {
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -109,6 +109,35 @@ static inline int libxl_cpumap_cpu_valid
 #define libxl_for_each_set_cpu(v, m) for (v = 0; v < (m).size * 8; v++) \
                                              if (libxl_cpumap_test(&(m), v))
 
+int libxl_nodemap_alloc(libxl_ctx *ctx, libxl_nodemap *nodemap);
+static inline int libxl_nodemap_test(libxl_nodemap *nodemap, int node)
+{
+    return libxl_map_test(nodemap, node);
+}
+static inline void libxl_nodemap_set(libxl_nodemap *nodemap, int node)
+{
+    libxl_map_set(nodemap, node);
+}
+static inline void libxl_nodemap_reset(libxl_nodemap *nodemap, int node)
+{
+    libxl_map_reset(nodemap, node);
+}
+static inline void libxl_nodemap_set_any(libxl_nodemap *nodemap)
+{
+    libxl_map_set_any(nodemap);
+}
+static inline void libxl_nodemap_set_none(libxl_nodemap *nodemap)
+{
+    libxl_map_set_none(nodemap);
+}
+static inline int libxl_nodemap_node_valid(libxl_nodemap *nodemap, int node)
+{
+    return libxl_map_elem_valid(nodemap, node);
+}
+#define libxl_for_each_node(var, map) for (var = 0; var < (map).size * 8; var++)
+#define libxl_for_each_set_node(v, m) for (v = 0; v < (m).size * 8; v++) \
+                                              if (libxl_nodemap_test(&(m), v))
+
 static inline uint32_t libxl__sizekb_to_mb(uint32_t s) {
     return (s + 1023) / 1024;
 }
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -116,6 +116,14 @@ int xenctl_cpumap_to_cpumask(cpumask_var
     return err;
 }
 
+int xenctl_nodemap_to_nodemask(nodemask_t *nodemask,
+                               const struct xenctl_map *xenctl_nodemap)
+{
+    return xenctl_map_to_bitmap(nodes_addr(*nodemask),
+                                xenctl_nodemap,
+                                MAX_NUMNODES);
+}
+
 static inline int is_free_domid(domid_t dom)
 {
     struct domain *d;