block/raw-win32: bdrv_parse_filename() for hdev

The "host_device" protocol driver should strip the "host_device:" prefix
from filenames if present.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

block/raw-win32.c

@@ -593,6 +593,15 @@ static int hdev_probe_device(const char *filename)
     return 0;
 }
 
+static void hdev_parse_filename(const char *filename, QDict *options,
+                                Error **errp)
+{
+    /* The prefix is optional, just as for "file". */
+    strstart(filename, "host_device:", &filename);
+
+    qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
+}
+
 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
                      Error **errp)
 {
@@ -663,6 +672,7 @@ static BlockDriver bdrv_host_device = {
     .protocol_name	= "host_device",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_needs_filename = true,
+    .bdrv_parse_filename = hdev_parse_filename,
     .bdrv_probe_device	= hdev_probe_device,
     .bdrv_file_open	= hdev_open,
     .bdrv_close		= raw_close,