Qemu/Xen: Fix early freeing MSIX MMIO memory region

msix->mmio is added to XenPCIPassthroughState's object as property.
object_finalize_child_property is called for XenPCIPassthroughState's
object, which calls object_property_del_all, which is going to try to
delete msix->mmio. object_finalize_child_property() will access
msix->mmio's obj. But the whole msix struct has already been freed
by xen_pt_msix_delete. This will cause segment fault when msix->mmio
has been overwritten.

This patch is to fix the issue.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 2b54f52..aa96288 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -938,10 +938,18 @@ static void xen_pci_passthrough_class_init(ObjectClass *klass, void *data)
     dc->props = xen_pci_passthrough_properties;
 };
 
+static void xen_pci_passthrough_finalize(Object *obj)
+{
+    XenPCIPassthroughState *s = XEN_PT_DEVICE(obj);
+
+    xen_pt_msix_delete(s);
+}
+
 static const TypeInfo xen_pci_passthrough_info = {
     .name = TYPE_XEN_PT_DEVICE,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(XenPCIPassthroughState),
+    .instance_finalize = xen_pci_passthrough_finalize,
     .class_init = xen_pci_passthrough_class_init,
 };