[PATCH v8 11/13] tools/libxl: introduce some socket helpers

[Chao Peng <chao.p.peng@linux.intel.com>]

Add libxl_socket_bitmap_alloc() to allow allocating a socket specific
libxl_bitmap (as it is for cpu/node bitmap).

Internal function libxl__count_physical_sockets() is introduced together
to get the socket count when the size of bitmap is not specified.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
Changes in v7:
* Broadcast LIBXL_HAVE_SOCKET_BITMAP_ALLOC
---
 tools/libxl/libxl.h          |  7 +++++++
 tools/libxl/libxl_internal.h |  2 ++
 tools/libxl/libxl_utils.c    | 46 ++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_utils.h    |  2 ++
 4 files changed, 57 insertions(+)

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 2ed7194..6ce93f5 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -768,6 +768,13 @@ void libxl_mac_copy(libxl_ctx *ctx, libxl_mac *dst, libxl_mac *src);
  */
 #define LIBXL_HAVE_PCITOPOLOGY 1
 
+/*
+ * LIBXL_HAVE_SOCKET_BITMAP_ALLOC
+ *
+ * If this is defined, then libxl_socket_bitmap_alloc exists.
+ */
+#define LIBXL_HAVE_SOCKET_BITMAP_ALLOC 1
+
 typedef char **libxl_string_list;
 void libxl_string_list_dispose(libxl_string_list *sl);
 int libxl_string_list_length(const libxl_string_list *sl);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 8aaa1ad..89ca694 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3697,6 +3697,8 @@ static inline void libxl__update_config_vtpm(libxl__gc *gc,
  */
 void libxl__bitmap_copy_best_effort(libxl__gc *gc, libxl_bitmap *dptr,
                                     const libxl_bitmap *sptr);
+
+int libxl__count_physical_sockets(libxl__gc *gc, int *sockets);
 #endif
 
 /*
diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index f6be2d7..bfc9699 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -840,6 +840,52 @@ int libxl_node_bitmap_alloc(libxl_ctx *ctx, libxl_bitmap *nodemap,
     return rc;
 }
 
+int libxl__count_physical_sockets(libxl__gc *gc, int *sockets)
+{
+    int rc;
+    libxl_physinfo info;
+
+    libxl_physinfo_init(&info);
+
+    rc = libxl_get_physinfo(CTX, &info);
+    if (rc)
+        return rc;
+
+    *sockets = info.nr_cpus / info.threads_per_core
+                            / info.cores_per_socket;
+
+    libxl_physinfo_dispose(&info);
+    return 0;
+}
+
+int libxl_socket_bitmap_alloc(libxl_ctx *ctx, libxl_bitmap *socketmap,
+                              int max_sockets)
+{
+    GC_INIT(ctx);
+    int rc = 0;
+
+    if (max_sockets < 0) {
+        rc = ERROR_INVAL;
+        LOG(ERROR, "invalid number of sockets provided");
+        goto out;
+    }
+
+    if (max_sockets == 0) {
+        rc = libxl__count_physical_sockets(gc, &max_sockets);
+        if (rc) {
+            LOGE(ERROR, "failed to get system socket count");
+            goto out;
+        }
+    }
+    /* This can't fail: no need to check and log */
+    libxl_bitmap_alloc(ctx, socketmap, max_sockets);
+
+ out:
+    GC_FREE;
+    return rc;
+
+}
+
 int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
                             const libxl_bitmap *nodemap,
                             libxl_bitmap *cpumap)
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
index 1c1761d..82340ec 100644
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -141,6 +141,8 @@ static inline int libxl_bitmap_equal(const libxl_bitmap *ba,
 int libxl_cpu_bitmap_alloc(libxl_ctx *ctx, libxl_bitmap *cpumap, int max_cpus);
 int libxl_node_bitmap_alloc(libxl_ctx *ctx, libxl_bitmap *nodemap,
                             int max_nodes);
+int libxl_socket_bitmap_alloc(libxl_ctx *ctx, libxl_bitmap *socketmap,
+                              int max_sockets);
 
 /* Populate cpumap with the cpus spanned by the nodes in nodemap */
 int libxl_nodemap_to_cpumap(libxl_ctx *ctx,
-- 
1.9.1