[PULL 17/38] qapi/qom: Add ObjectOptions for rng-*, deprecate 'opened'

[Kevin Wolf <kwolf@redhat.com>]

This adds a QAPI schema for the properties of the rng-* objects.

The 'opened' property doesn't seem to make sense as an external
interface: It is automatically set to true in ucc->complete, and
explicitly setting it to true earlier just means that trying to set
additional options will result in an error. After the property has once
been set to true (i.e. when the object construction has completed), it
can never be reset to false. In other words, the 'opened' property is
useless. Mark it as deprecated in the schema from the start.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qapi/qom.json              | 56 ++++++++++++++++++++++++++++++++++++--
 docs/system/deprecated.rst |  9 ++++++
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/qapi/qom.json b/qapi/qom.json
index 79525f64a1..7fb243c3ab 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -382,6 +382,52 @@
             '*hugetlbsize': 'size',
             '*seal': 'bool' } }
 
+##
+# @RngProperties:
+#
+# Properties for objects of classes derived from rng.
+#
+# @opened: if true, the device is opened immediately when applying this option
+#          and will probably fail when processing the next option. Don't use;
+#          only provided for compatibility. (default: false)
+#
+# Features:
+# @deprecated: Member @opened is deprecated.  Setting true doesn't make sense,
+#              and false is already the default.
+#
+# Since: 1.3
+##
+{ 'struct': 'RngProperties',
+  'data': { '*opened': { 'type': 'bool', 'features': ['deprecated'] } } }
+
+##
+# @RngEgdProperties:
+#
+# Properties for rng-egd objects.
+#
+# @chardev: the name of a character device backend that provides the connection
+#           to the RNG daemon
+#
+# Since: 1.3
+##
+{ 'struct': 'RngEgdProperties',
+  'base': 'RngProperties',
+  'data': { 'chardev': 'str' } }
+
+##
+# @RngRandomProperties:
+#
+# Properties for rng-random objects.
+#
+# @filename: the filename of the device on the host to obtain entropy from
+#            (default: "/dev/urandom")
+#
+# Since: 1.3
+##
+{ 'struct': 'RngRandomProperties',
+  'base': 'RngProperties',
+  'data': { '*filename': 'str' } }
+
 ##
 # @ObjectType:
 #
@@ -402,7 +448,10 @@
     'memory-backend-file',
     { 'name': 'memory-backend-memfd',
       'if': 'defined(CONFIG_LINUX)' },
-    'memory-backend-ram'
+    'memory-backend-ram',
+    'rng-builtin',
+    'rng-egd',
+    'rng-random'
   ] }
 
 ##
@@ -434,7 +483,10 @@
       'memory-backend-file':        'MemoryBackendFileProperties',
       'memory-backend-memfd':       { 'type': 'MemoryBackendMemfdProperties',
                                       'if': 'defined(CONFIG_LINUX)' },
-      'memory-backend-ram':         'MemoryBackendProperties'
+      'memory-backend-ram':         'MemoryBackendProperties',
+      'rng-builtin':                'RngProperties',
+      'rng-egd':                    'RngEgdProperties',
+      'rng-random':                 'RngRandomProperties'
   } }
 
 ##
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index e6c2ba2d4d..3ce4fe7581 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -166,6 +166,15 @@ Using ``-M kernel-irqchip=off`` with x86 machine types that include a local
 APIC is deprecated.  The ``split`` setting is supported, as is using
 ``-M kernel-irqchip=off`` with the ISA PC machine type.
 
+``opened`` property of ``rng-*`` objects (since 6.0.0)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+The only effect of specifying ``opened=on`` in the command line or QMP
+``object-add`` is that the device is opened immediately, possibly before all
+other options have been processed.  This will either have no effect (if
+``opened`` was the last option) or cause errors.  The property is therefore
+useless and should not be specified.
+
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
 
-- 
2.29.2