[PULL 31/45] qmp: Include "reserve" property of memory backends

[Paolo Bonzini <pbonzini@redhat.com>]

From: David Hildenbrand <david@redhat.com>

Let's include the new property. Instead of relying on CONFIG_LINUX,
let's try to unconditionally grab the property and treat errors as
"does not exist".

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-15-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/core/machine-qmp-cmds.c | 7 +++++++
 qapi/machine.json          | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c
index a36ceaf4f3..216fdfaf3a 100644
--- a/hw/core/machine-qmp-cmds.c
+++ b/hw/core/machine-qmp-cmds.c
@@ -157,6 +157,7 @@ void qmp_set_numa_node(NumaOptions *cmd, Error **errp)
 
 static int query_memdev(Object *obj, void *opaque)
 {
+    Error *err = NULL;
     MemdevList **list = opaque;
     Memdev *m;
     QObject *host_nodes;
@@ -173,6 +174,12 @@ static int query_memdev(Object *obj, void *opaque)
         m->dump = object_property_get_bool(obj, "dump", &error_abort);
         m->prealloc = object_property_get_bool(obj, "prealloc", &error_abort);
         m->share = object_property_get_bool(obj, "share", &error_abort);
+        m->reserve = object_property_get_bool(obj, "reserve", &err);
+        if (err) {
+            error_free_or_abort(&err);
+        } else {
+            m->has_reserve = true;
+        }
         m->policy = object_property_get_enum(obj, "policy", "HostMemPolicy",
                                              &error_abort);
         host_nodes = object_property_get_qobject(obj,
diff --git a/qapi/machine.json b/qapi/machine.json
index 1395742a4a..e4d0f9b24f 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -798,6 +798,12 @@
 #
 # @share: whether memory is private to QEMU or shared (since 6.1)
 #
+# @reserve: whether swap space (or huge pages) was reserved if applicable.
+#           This corresponds to the user configuration and not the actual
+#           behavior implemented in the OS to perform the reservation.
+#           For example, Linux will never reserve swap space for shared
+#           file mappings. (since 6.1)
+#
 # @host-nodes: host nodes for its memory policy
 #
 # @policy: memory policy of memory backend
@@ -812,6 +818,7 @@
     'dump':       'bool',
     'prealloc':   'bool',
     'share':      'bool',
+    '*reserve':    'bool',
     'host-nodes': ['uint16'],
     'policy':     'HostMemPolicy' }}
 
-- 
2.31.1