Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 73 insertions, 0 deletions

diff --git a/hw/s390x/vhost-vsock-ccw.c b/hw/s390x/vhost-vsock-ccw.c
new file mode 100644
index 000000000..246416a8f
--- /dev/null
+++ b/hw/s390x/vhost-vsock-ccw.c
@@ -0,0 +1,73 @@
+/*
+ * vhost vsock ccw implementation
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio.h"
+#include "qapi/error.h"
+#include "qemu/module.h"
+#include "virtio-ccw.h"
+
+static Property vhost_vsock_ccw_properties[] = {
+    DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
+                       VIRTIO_CCW_MAX_REV),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_vsock_ccw_realize(VirtioCcwDevice *ccw_dev, Error **errp)
+{
+    VHostVSockCCWState *dev = VHOST_VSOCK_CCW(ccw_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    qdev_realize(vdev, BUS(&ccw_dev->bus), errp);
+}
+
+static void vhost_vsock_ccw_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
+
+    k->realize = vhost_vsock_ccw_realize;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    device_class_set_props(dc, vhost_vsock_ccw_properties);
+}
+
+static void vhost_vsock_ccw_instance_init(Object *obj)
+{
+    VHostVSockCCWState *dev = VHOST_VSOCK_CCW(obj);
+    VirtioCcwDevice *ccw_dev = VIRTIO_CCW_DEVICE(obj);
+    VirtIODevice *virtio_dev;
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_VSOCK);
+
+    virtio_dev = VIRTIO_DEVICE(&dev->vdev);
+
+    /*
+     * To avoid migration issues, we force virtio version 1 only when
+     * legacy check is enabled in the new machine types (>= 5.1).
+     */
+    if (!virtio_legacy_check_disabled(virtio_dev)) {
+        ccw_dev->force_revision_1 = true;
+    }
+}
+
+static const TypeInfo vhost_vsock_ccw_info = {
+    .name          = TYPE_VHOST_VSOCK_CCW,
+    .parent        = TYPE_VIRTIO_CCW_DEVICE,
+    .instance_size = sizeof(VHostVSockCCWState),
+    .instance_init = vhost_vsock_ccw_instance_init,
+    .class_init    = vhost_vsock_ccw_class_init,
+};
+
+static void vhost_vsock_ccw_register(void)
+{
+    type_register_static(&vhost_vsock_ccw_info);
+}
+
+type_init(vhost_vsock_ccw_register)