tools: Introduce a non-truncating xc_xenver_cmdline()

Update libxl to match.  No API/ABI change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

tools/include/xenctrl.h

@@ -1580,6 +1580,7 @@ int xc_version(xc_interface *xch, int cmd, void *arg);
 char *xc_xenver_extraversion(xc_interface *xch);
 char *xc_xenver_capabilities(xc_interface *xch);
 char *xc_xenver_changeset(xc_interface *xch);
+char *xc_xenver_commandline(xc_interface *xch);
 
 int xc_flask_op(xc_interface *xch, xen_flask_op_t *op);
 

tools/libs/ctrl/xc_version.c

@@ -166,3 +166,8 @@ char *xc_xenver_changeset(xc_interface *xch)
 {
     return varbuf_simple_string(xch, XENVER_changeset2);
 }
+
+char *xc_xenver_commandline(xc_interface *xch)
+{
+    return varbuf_simple_string(xch, XENVER_commandline2);
+}

tools/libs/light/libxl.c

@@ -584,7 +584,6 @@ const libxl_version_info* libxl_get_version_info(libxl_ctx *ctx)
     union {
         xen_compile_info_t xen_cc;
         xen_platform_parameters_t p_parms;
-        xen_commandline_t xen_commandline;
         xen_build_id_t build_id;
     } u;
     long xen_version;
@@ -614,8 +613,7 @@ const libxl_version_info* libxl_get_version_info(libxl_ctx *ctx)
 
     info->pagesize = xc_version(ctx->xch, XENVER_pagesize, NULL);
 
-    xc_version(ctx->xch, XENVER_commandline, &u.xen_commandline);
-    info->commandline = libxl__strdup(NOGC, u.xen_commandline);
+    info->commandline = xc_xenver_commandline(ctx->xch);
 
     u.build_id.len = sizeof(u) - sizeof(u.build_id);
     r = libxl__xc_version_wrap(gc, info, &u.build_id);