From c63a58b4e1d3db52301bec072ac8025216731f35 Mon Sep 17 00:00:00 2001
From: Eduardo Habkost <ehabkost@redhat.com>
Date: Wed, 16 Jan 2019 23:18:18 +0000
Subject: [PATCH 3/7] globals: Allow global properties to be optional
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RH-Author: Eduardo Habkost <ehabkost@redhat.com>
Message-id: <20190116231819.29310-4-ehabkost@redhat.com>
Patchwork-id: 84029
O-Subject: [RHEL-8.0/AV qemu-kvm PATCH 3/4] globals: Allow global properties to be optional
Bugzilla: 1648023
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

Upstream tree: git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git
Upstream commit: d7741743f4f3d2683d1bb6938f88dc0167c21afa

Making some global properties optional will let us simplify
compat code when a given property works on most (but not all)
subclasses of a given type.

Device types will be able to opt out from optional compat
properties by simply not registering those properties.

Backport conflict notes:
    Patching qdev_prop_set_globals(), because our downstream tree
    still doesn't have object_apply_global_props() from commit
    ea9ce8934c5d ("hw: apply accel compat properties without
    touching globals")

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/core/qdev-properties.c | 3 +++
 include/hw/qdev-core.h    | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 35072de..2023c1a 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -1255,6 +1255,9 @@ void qdev_prop_set_globals(DeviceState *dev)
         if (object_dynamic_cast(OBJECT(dev), prop->driver) == NULL) {
             continue;
         }
+        if (prop->optional && !object_property_find(OBJECT(dev), prop->property, NULL)) {
+            continue;
+        }
         prop->used = true;
         object_property_parse(OBJECT(dev), prop->value, prop->property, &err);
         if (err != NULL) {
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index a24d0dd..a10f60f 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -252,6 +252,8 @@ struct PropertyInfo {
  * @user_provided: Set to true if property comes from user-provided config
  * (command-line or config file).
  * @used: Set to true if property was used when initializing a device.
+ * @optional: If set to true, GlobalProperty will be skipped without errors
+ *            if the property doesn't exist.
  * @errp: Error destination, used like first argument of error_setg()
  *        in case property setting fails later. If @errp is NULL, we
  *        print warnings instead of ignoring errors silently. For
@@ -264,6 +266,7 @@ typedef struct GlobalProperty {
     const char *value;
     bool user_provided;
     bool used;
+    bool optional;
     Error **errp;
 } GlobalProperty;
 
-- 
1.8.3.1