usb/vmstate: add parent dev path

... to make vmstate id string truely unique with multiple host
controllers, i.e. move from "1/usb-ptr" to "0000:00:01.3/1/usb-ptr"
(usb tabled connected to piix3 uhci).

This obviously breaks migration.  To handle this the usb bus
property "full-path" is added.  When setting this to false old
behavior is maintained.  This way current qemu will be compatible
with old versions when started using '-M pc-$oldversion'.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/hw/usb.h b/hw/usb.h
index e95085f0b3..ae7ccda18c 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -182,12 +182,17 @@ struct USBEndpoint {
     QTAILQ_HEAD(, USBPacket) queue;
 };
 
+enum USBDeviceFlags {
+    USB_DEV_FLAG_FULL_PATH,
+};
+
 /* definition of a USB device */
 struct USBDevice {
     DeviceState qdev;
     USBPort *port;
     char *port_path;
     void *opaque;
+    uint32_t flags;
 
     /* Actual connected speed */
     int speed;