monitor: allow device_del to accept QOM paths

Currently device_del requires that the client provide the
device short ID. device_add allows devices to be created
without giving an ID, at which point there is no way to
delete them with device_del. The QOM object path, however,
provides an alternative way to identify the devices.

Allowing device_del to accept an object path ensures all
devices are deletable regardless of whether they have an
ID.

 (qemu) device_add usb-mouse
 (qemu) qom-list /machine/peripheral-anon
 device[0] (child<usb-mouse>)
 type (string)
 (qemu) device_del /machine/peripheral-anon/device[0]

Devices are required to be marked as hotpluggable
otherwise an error is raised

 (qemu) device_del /machine/unattached/device[4]
 Device 'PIIX3' does not support hotplugging

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1441974836-17476-1-git-send-email-berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Commit message touched up, accidental white-space change dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/qmp-commands.hx b/qmp-commands.hx
index 66f03007ec..d2ba800d5e 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -321,13 +321,18 @@ Remove a device.
 
 Arguments:
 
-- "id": the device's ID (json-string)
+- "id": the device's ID or QOM path (json-string)
 
 Example:
 
 -> { "execute": "device_del", "arguments": { "id": "net1" } }
 <- { "return": {} }
 
+Example:
+
+-> { "execute": "device_del", "arguments": { "id": "/machine/peripheral-anon/device[0]" } }
+<- { "return": {} }
+
 EQMP
 
     {