[PATCH v1 01/10] libxl: libxl-json format and internal functions to get / set it

[Wei Liu <wei.liu2@citrix.com>]

Introduce a new format in libxl userdata store called "libxl-json". This
file format contains JSON version of libxl_domain_config, generated by
libxl.

Two internal functions to get and set libxl_domain_configuration
are also introduced.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl.h          |    2 ++
 tools/libxl/libxl_internal.c |   56 ++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_internal.h |   10 ++++++++
 3 files changed, 68 insertions(+)

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index e6e0301..2dc6a51 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -1182,6 +1182,8 @@ void libxl_cpuid_set(libxl_ctx *ctx, uint32_t domid,
  *  "xl"          domain config file in xl format, Unix line endings
  *  "libvirt-xml" domain config file in libvirt XML format.  See
  *                http://libvirt.org/formatdomain.html
+ *  "libxl-json"  libxl_domain_config object in JSON format, generated
+ *                by libxl
  *
  * libxl does not enforce the registration of userdata userids or the
  * semantics of the data.  For specifications of the data formats
diff --git a/tools/libxl/libxl_internal.c b/tools/libxl/libxl_internal.c
index 81f8985..dc47177 100644
--- a/tools/libxl/libxl_internal.c
+++ b/tools/libxl/libxl_internal.c
@@ -381,6 +381,62 @@ out:
     return rc;
 }
 
+int libxl__get_domain_configuration(libxl__gc *gc, uint32_t domid,
+                                    libxl_domain_config *d_config)
+{
+    uint8_t *data = NULL;
+    int rc, len;
+
+    rc = libxl_userdata_retrieve(CTX, domid, "libxl-json", &data, &len);
+    if (rc) {
+        LOGEV(ERROR, rc,
+              "failed to retrieve domain configuration for domain %d", domid);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    if (len == 0) {
+        LOGE(ERROR, "configuration data stream empty for domain %d", domid);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+    rc = libxl_domain_config_from_json(CTX, d_config, (const char *)data);
+
+out:
+    free(data);
+    return rc;
+}
+
+int libxl__set_domain_configuration(libxl__gc *gc, uint32_t domid,
+                                    libxl_domain_config *d_config)
+{
+    char *d_config_json;
+    int rc;
+
+    d_config_json = libxl_domain_config_to_json(CTX, d_config);
+    if (!d_config_json) {
+        LOGE(ERROR, "failed to convert domain configuration to JSON for domain %d",
+             domid);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    rc = libxl_userdata_store(CTX, domid, "libxl-json",
+                              (const uint8_t *)d_config_json,
+                              strlen(d_config_json) + 1 /* include '\0' */);
+    if (rc) {
+        LOGEV(ERROR, rc, "failed to store domain configuration for domain %d",
+              domid);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+out:
+    free(d_config_json);
+    return rc;
+}
+
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index beb052e..ef2111b 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3219,6 +3219,16 @@ static inline int libxl__key_value_list_is_empty(libxl_key_value_list *pkvl)
 
 int libxl__cpuid_policy_is_empty(libxl_cpuid_policy_list *pl);
 
+/*
+ * Retrieve / store domain configuration from / to libxl private
+ * data store. The registry entry in libxl private data store
+ * is "libxl-json".
+ */
+int libxl__get_domain_configuration(libxl__gc *gc, uint32_t domid,
+                                    libxl_domain_config *d_config);
+int libxl__set_domain_configuration(libxl__gc *gc, uint32_t domid,
+                                    libxl_domain_config *d_config);
+
 #endif
 
 /*
-- 
1.7.10.4