Make blktap support optional.

Enable it by default on Linux, disable it on non-Linux.

Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
committer: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 51 insertions, 0 deletions

diff --git a/tools/libxl/libxl_blktap2.c b/tools/libxl/libxl_blktap2.c
new file mode 100644
index 0000000000..17c18fbfdf
--- /dev/null
+++ b/tools/libxl/libxl_blktap2.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2010      Advanced Micro Devices
+ * Author Christoph Egger <Christoph.Egger@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl.h"
+#include "libxl_osdeps.h"
+#include "libxl_internal.h"
+
+#include "tap-ctl.h"
+
+int libxl_blktap_enabled(libxl_gc *gc)
+{
+    const char *msg;
+    return !tap_ctl_check(&msg);
+}
+
+const char *libxl_blktap_devpath(libxl_gc *gc,
+                                 const char *disk,
+                                 libxl_disk_phystype phystype)
+{
+    const char *type;
+    char *params, *devname;
+    int minor, err;
+
+    type = device_disk_string_of_phystype(phystype);
+    minor = tap_ctl_find_minor(type, disk);
+    if (minor >= 0) {
+        devname = libxl_sprintf(gc, "/dev/xen/blktap-2/tapdev%d", minor);
+        if (devname)
+            return devname;
+    }
+
+    params = libxl_sprintf(gc, "%s:%s", type, disk);
+    err = tap_ctl_create(params, &devname);
+    if (!err) {
+        libxl_ptr_add(gc, devname);
+        return devname;
+    }
+
+    return NULL;
+}