[PULL 1/2] xen: Fix xen-legacy-backend qdev types

[Anthony PERARD <anthony.perard@citrix.com>]

From: Jason Andryuk <jandryuk@gmail.com>

xen-sysdev is a TYPE_SYS_BUS_DEVICE.  bus_type should not be changed so
that it can plug into the System bus.  Otherwise this assert triggers:
qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
`dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
failed.

TYPE_XENBACKEND attaches to TYPE_XENSYSBUS, so its class_init needs to
be set accordingly to attach the qdev.  Otherwise the following assert
triggers:
qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
`dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
failed.

TYPE_XENBACKEND is not a subclass of XEN_XENSYSDEV, so it's parent
is just TYPE_DEVICE.  Change that.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Paul Durrant <pdurrant@amazon.com>
Fixes: 81cb05732efb ("qdev: Assert devices are plugged into a bus that can take them")
Message-Id: <20200624121939.10282-1-jandryuk@gmail.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
 hw/xen/xen-legacy-backend.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index 7d4b13351e06..083d8dc1b28b 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -789,11 +789,12 @@ static void xendev_class_init(ObjectClass *klass, void *data)
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     /* xen-backend devices can be plugged/unplugged dynamically */
     dc->user_creatable = true;
+    dc->bus_type = TYPE_XENSYSBUS;
 }
 
 static const TypeInfo xendev_type_info = {
     .name          = TYPE_XENBACKEND,
-    .parent        = TYPE_XENSYSDEV,
+    .parent        = TYPE_DEVICE,
     .class_init    = xendev_class_init,
     .instance_size = sizeof(struct XenLegacyDevice),
 };
@@ -824,7 +825,6 @@ static void xen_sysdev_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     device_class_set_props(dc, xen_sysdev_properties);
-    dc->bus_type = TYPE_XENSYSBUS;
 }
 
 static const TypeInfo xensysdev_info = {
-- 
Anthony PERARD