hw/ppc: modified the condition for usb controllers to be created for some ppc machines

Some ppc machines create a default usb controller based on a 'machine condition'.
Until now the logic was: create the usb controller if:
 -  the usb option was supplied in cli and value is true or
 -  the usb option was absent and both set_defaults and the machine
    condition were true.

Modified the logic to:
Create the usb controller if:
 - the machine condition is true and defaults are enabled or
 - the usb option is supplied and true.

The main for this is to simplify the usb_enabled method.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-id: 1420550957-22337-2-git-send-email-marcel@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/vl.c b/vl.c
index bea9656232..415535fb46 100644
--- a/vl.c
+++ b/vl.c
@@ -997,10 +997,15 @@ static int parse_name(QemuOpts *opts, void *opaque)
     return 0;
 }
 
+bool defaults_enabled(void)
+{
+    return has_defaults;
+}
+
 bool usb_enabled(bool default_usb)
 {
     return qemu_opt_get_bool(qemu_get_machine_opts(), "usb",
-                             has_defaults && default_usb);
+                             default_usb);
 }
 
 #ifndef _WIN32