[PATCH 07 of 10 v2] libxl: introduce some node map helpers

[Dario Faggioli <raistlin@linux.it>]

To allow for allocating a node specific libxl_bitmap (as it
is for cpu number and maps). Helper unctions to convert a node
map it its coresponding cpu map and vice versa are also
implemented.

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

Changes from v1:
 * This patch replaces "libxl: introduce libxl_nodemap", as
   the libxl_bitmap type introduced by the previous patch is
   now used for both cpu and node maps, as requested during
   v1 review.

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
@@ -556,6 +556,50 @@ void libxl_bitmap_reset(libxl_bitmap *bi
     bitmap->map[bit / 8] &= ~(1 << (bit & 7));
 }
 
+int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
+                            const libxl_bitmap *nodemap,
+                            libxl_bitmap *cpumap)
+{
+    libxl_cputopology *tinfo = NULL;
+    int nr_cpus, i, rc = 0;
+
+    tinfo = libxl_get_cpu_topology(ctx, &nr_cpus);
+    if (tinfo == NULL) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    libxl_bitmap_set_none(cpumap);
+    for (i = 0; i < nr_cpus; i++) {
+        if (libxl_bitmap_test(nodemap, tinfo[i].node))
+            libxl_bitmap_set(cpumap, i);
+    }
+ out:
+    libxl_cputopology_list_free(tinfo, nr_cpus);
+    return rc;
+}
+
+int libxl_cpumap_to_nodemap(libxl_ctx *ctx,
+                            const libxl_bitmap *cpumap,
+                            libxl_bitmap *nodemap)
+{
+    libxl_cputopology *tinfo = NULL;
+    int nr_cpus, i, rc = 0;
+
+    tinfo = libxl_get_cpu_topology(ctx, &nr_cpus);
+    if (tinfo == NULL) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    libxl_bitmap_set_none(nodemap);
+    libxl_for_each_set_bit(i, *cpumap)
+        libxl_bitmap_set(nodemap, tinfo[i].node);
+ out:
+    libxl_cputopology_list_free(tinfo, nr_cpus);
+    return rc;
+}
+
 int libxl_get_max_cpus(libxl_ctx *ctx)
 {
     return xc_get_max_cpus(ctx->xch);
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
@@ -100,6 +100,27 @@ static inline int libxl_cpu_bitmap_alloc
     return libxl_bitmap_alloc(ctx, cpumap, max_cpus);
 }
 
+static inline int libxl_node_bitmap_alloc(libxl_ctx *ctx,
+                                          libxl_bitmap *nodemap)
+{
+    int max_nodes;
+
+    max_nodes = libxl_get_max_nodes(ctx);
+    if (max_nodes == 0)
+        return ERROR_FAIL;
+
+    return libxl_bitmap_alloc(ctx, nodemap, max_nodes);
+}
+
+int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
+                            const libxl_bitmap *nodemap,
+                            libxl_bitmap *cpumap);
+    /* populate cpumap with the cpus spanned by the nodes in nodemap */
+int libxl_cpumap_to_nodemap(libxl_ctx *ctx,
+                            const libxl_bitmap *cpuemap,
+                            libxl_bitmap *nodemap);
+    /* populate nodemap with the nodes of the cpus in cpumap */
+
 static inline uint32_t libxl__sizekb_to_mb(uint32_t s) {
     return (s + 1023) / 1024;
 }