vl: Create block backends before setting machine properties

qemu-system-FOO's main() acts on command line arguments in its own
idiosyncratic order.  There's not much method to its madness.
Whenever we find a case where one kind of command line argument needs
to refer to something created for another kind later, we rejigger the
order.

Block devices get created long after machine properties get processed.
Therefore, block device machine properties can be created, but not
set.  No such properties exist.  But the next commit will create some.
Time to rejigger again: create block devices earlier.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190308131445.17502-8-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/vl.c b/vl.c
index c22ca447fa480673e9ecfbddad5e8b2965c4d3c4..e9239d55ad6afc431c16cb9602e167c6ac95b9a1 100644 (file)
--- a/vl.c
+++ b/vl.c
@@ -4274,6 +4274,13 @@ int main(int argc, char **argv, char **envp)
         exit(0);
     }
 
+    /*
+     * Note: we need to create block backends before
+     * machine_set_property(), so machine properties can refer to
+     * them.
+     */
+    configure_blockdev(&bdo_queue, machine_class, snapshot);
+
     machine_opts = qemu_get_machine_opts();
     qemu_opt_foreach(machine_opts, machine_set_property, current_machine,
                      &error_fatal);
@@ -4400,8 +4407,6 @@ int main(int argc, char **argv, char **envp)
     ram_mig_init();
     dirty_bitmap_mig_init();
 
-    configure_blockdev(&bdo_queue, machine_class, snapshot);
-
     qemu_opts_foreach(qemu_find_opts("mon"),
                       mon_init_func, NULL, &error_fatal);