allow if=none for drive_add

Allow adding unconnected host drives by specifying if=none like it is
possible with -drive.  They can be put in use with drive attributes,
like this:

  drive_add dummy if=none,id=mydisk,file=/some/disk.img
  device_add virtio-blk-pci,drive=mydisk

which is the monitor aequivalent to these command line switches:

  -drive if=none,id=mydisk,file=/some/disk.img
  -device virtio-blk-pci,drive=mydisk

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c
index 833d5d8a98..d40a3bd0cd 100644
--- a/hw/pci-hotplug.c
+++ b/hw/pci-hotplug.c
@@ -91,6 +91,9 @@ void drive_hot_add(Monitor *mon, const QDict *qdict)
                        dinfo->bus,
                        dinfo->unit);
         break;
+    case IF_NONE:
+        monitor_printf(mon, "OK\n");
+        break;
     default:
         monitor_printf(mon, "Can't hot-add drive to type %d\n", type);
         goto err;