[PATCH 04/15] libxl: introduce libxl_node_to_cpumap

[Dario Faggioli <dario.faggioli@citrix.com>]

As an helper for the special case (of libxl_nodemap_to_cpumap) when
one wants the cpumap for just one node.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
Picking this up from a previously submitted series ("xl:
allow for node-wise specification of vcpu pinning") as the
changes in that and in this series would otherwise be
conflicting. If this is considered fine, Feel free to apply
it from here and skip the corresponding e-mail in the
original submission.
---
 tools/libxl/libxl_utils.c |   22 ++++++++++++++++++++++
 tools/libxl/libxl_utils.h |    3 +++
 2 files changed, 25 insertions(+)

diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index 4309e5e..5c125e6 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -668,6 +668,28 @@ int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
     return rc;
 }
 
+int libxl_node_to_cpumap(libxl_ctx *ctx, int node,
+                         libxl_bitmap *cpumap)
+{
+    libxl_bitmap nodemap;
+    int rc = 0;
+
+    libxl_bitmap_init(&nodemap);
+
+    rc = libxl_node_bitmap_alloc(ctx, &nodemap, 0);
+    if (rc)
+        goto out;
+
+    libxl_bitmap_set_none(&nodemap);
+    libxl_bitmap_set(&nodemap, node);
+
+    rc = libxl_nodemap_to_cpumap(ctx, &nodemap, cpumap);
+
+ out:
+    libxl_bitmap_dispose(&nodemap);
+    return rc;
+}
+
 int libxl_cpumap_to_nodemap(libxl_ctx *ctx,
                             const libxl_bitmap *cpumap,
                             libxl_bitmap *nodemap)
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
index a430362..7b84e6a 100644
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -129,6 +129,9 @@ static inline int libxl_node_bitmap_alloc(libxl_ctx *ctx,
 int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
                             const libxl_bitmap *nodemap,
                             libxl_bitmap *cpumap);
+/* Populate cpumap with the cpus spanned by node */
+int libxl_node_to_cpumap(libxl_ctx *ctx, int node,
+                         libxl_bitmap *cpumap);
 /* Populate nodemap with the nodes of the cpus in cpumap */
 int libxl_cpumap_to_nodemap(libxl_ctx *ctx,
                             const libxl_bitmap *cpuemap,