[Qemu-devel] [PATCH 4/7] virtio-blk: use aliases instead of duplicate qdev properties

[Stefan Hajnoczi <stefanha@redhat.com>]

virtio-blk-pci, virtio-blk-s390, and virtio-blk-ccw all duplicate the
qdev properties of their VirtIOBlock child.  This approach does not work
well with string or pointer properties since we must be careful about
leaking or double-freeing them.

Use the QOM alias property to forward property accesses to the
VirtIOBlock child.  This way no duplication is necessary.

Remember to stop calling virtio_blk_set_conf() so that we don't clobber
the values already set on the VirtIOBlock instance.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/virtio-blk.c          | 24 ++++++++++++++++++++++++
 hw/s390x/s390-virtio-bus.c     |  9 +--------
 hw/s390x/s390-virtio-bus.h     |  1 -
 hw/s390x/virtio-ccw.c          |  3 +--
 hw/s390x/virtio-ccw.h          |  1 -
 hw/virtio/virtio-pci.c         |  3 +--
 hw/virtio/virtio-pci.h         |  1 -
 include/hw/virtio/virtio-blk.h |  2 ++
 8 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 8a568e5..52cd3c9 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -754,6 +754,30 @@ static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
     virtio_cleanup(vdev);
 }
 
+void virtio_blk_add_child_aliases(Object *obj, VirtIOBlock *s)
+{
+    const char *aliases[] = {"drive", "logical_block_size",
+        "physical_block_size", "min_io_size", "opt_io_size", "bootindex",
+        "discard_granularity", "cyls", "heads", "secs", "serial", "config-wce",
+        "x-iothread",
+#ifdef __linux__
+        "scsi",
+#endif
+#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
+        "x-data-plane",
+#endif
+        NULL
+    };
+    Object *child = OBJECT(s);
+    int i;
+
+    for (i = 0; aliases[i]; i++) {
+        object_property_add_alias(obj, aliases[i],
+                                  child, aliases[i],
+                                  &error_abort);
+    }
+}
+
 static Property virtio_blk_properties[] = {
     DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlock, blk),
     DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index 9c71afa..e7efcdb 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -179,7 +179,6 @@ static int s390_virtio_blk_init(VirtIOS390Device *s390_dev)
 {
     VirtIOBlkS390 *dev = VIRTIO_BLK_S390(s390_dev);
     DeviceState *vdev = DEVICE(&dev->vdev);
-    virtio_blk_set_conf(vdev, &(dev->blk));
     qdev_set_parent_bus(vdev, BUS(&s390_dev->bus));
     if (qdev_init(vdev) < 0) {
         return -1;
@@ -192,6 +191,7 @@ static void s390_virtio_blk_instance_init(Object *obj)
     VirtIOBlkS390 *dev = VIRTIO_BLK_S390(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    virtio_blk_add_child_aliases(obj, &dev->vdev);
 }
 
 static int s390_virtio_serial_init(VirtIOS390Device *s390_dev)
@@ -526,18 +526,11 @@ static const TypeInfo s390_virtio_net = {
     .class_init    = s390_virtio_net_class_init,
 };
 
-static Property s390_virtio_blk_properties[] = {
-    DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlkS390, blk),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void s390_virtio_blk_class_init(ObjectClass *klass, void *data)
 {
-    DeviceClass *dc = DEVICE_CLASS(klass);
     VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
 
     k->init = s390_virtio_blk_init;
-    dc->props = s390_virtio_blk_properties;
 }
 
 static const TypeInfo s390_virtio_blk = {
diff --git a/hw/s390x/s390-virtio-bus.h b/hw/s390x/s390-virtio-bus.h
index ac81bd8..ffd0df7 100644
--- a/hw/s390x/s390-virtio-bus.h
+++ b/hw/s390x/s390-virtio-bus.h
@@ -124,7 +124,6 @@ void s390_virtio_reset_idx(VirtIOS390Device *dev);
 typedef struct VirtIOBlkS390 {
     VirtIOS390Device parent_obj;
     VirtIOBlock vdev;
-    VirtIOBlkConf blk;
 } VirtIOBlkS390;
 
 /* virtio-scsi-s390 */
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 082bb42..9e98713 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -725,7 +725,6 @@ static int virtio_ccw_blk_init(VirtioCcwDevice *ccw_dev)
 {
     VirtIOBlkCcw *dev = VIRTIO_BLK_CCW(ccw_dev);
     DeviceState *vdev = DEVICE(&dev->vdev);
-    virtio_blk_set_conf(vdev, &(dev->blk));
     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
     if (qdev_init(vdev) < 0) {
         return -1;
@@ -739,6 +738,7 @@ static void virtio_ccw_blk_instance_init(Object *obj)
     VirtIOBlkCcw *dev = VIRTIO_BLK_CCW(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    virtio_blk_add_child_aliases(obj, &dev->vdev);
 }
 
 static int virtio_ccw_serial_init(VirtioCcwDevice *ccw_dev)
@@ -1126,7 +1126,6 @@ static const TypeInfo virtio_ccw_net = {
 static Property virtio_ccw_blk_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
     DEFINE_VIRTIO_BLK_FEATURES(VirtioCcwDevice, host_features[0]),
-    DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlkCcw, blk),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index 4393e44..7eea6b9 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -134,7 +134,6 @@ typedef struct VHostSCSICcw {
 typedef struct VirtIOBlkCcw {
     VirtioCcwDevice parent_obj;
     VirtIOBlock vdev;
-    VirtIOBlkConf blk;
 } VirtIOBlkCcw;
 
 /* virtio-balloon-ccw */
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 0751a1e..c13fb09 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1068,7 +1068,6 @@ static Property virtio_blk_pci_properties[] = {
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
     DEFINE_VIRTIO_BLK_FEATURES(VirtIOPCIProxy, host_features),
-    DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlkPCI, blk),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1076,7 +1075,6 @@ static int virtio_blk_pci_init(VirtIOPCIProxy *vpci_dev)
 {
     VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(vpci_dev);
     DeviceState *vdev = DEVICE(&dev->vdev);
-    virtio_blk_set_conf(vdev, &(dev->blk));
     qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
     if (qdev_init(vdev) < 0) {
         return -1;
@@ -1104,6 +1102,7 @@ static void virtio_blk_pci_instance_init(Object *obj)
     VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BLK);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    virtio_blk_add_child_aliases(obj, &dev->vdev);
 }
 
 static const TypeInfo virtio_blk_pci_info = {
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index dc332ae..1cea157 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -131,7 +131,6 @@ struct VHostSCSIPCI {
 struct VirtIOBlkPCI {
     VirtIOPCIProxy parent_obj;
     VirtIOBlock vdev;
-    VirtIOBlkConf blk;
 };
 
 /*
diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h
index 78e7f81..bea540c 100644
--- a/include/hw/virtio/virtio-blk.h
+++ b/include/hw/virtio/virtio-blk.h
@@ -161,4 +161,6 @@ typedef struct VirtIOBlock {
 
 void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk);
 
+void virtio_blk_add_child_aliases(Object *obj, VirtIOBlock *s);
+
 #endif
-- 
1.9.0