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, 139 insertions, 0 deletions

diff --git a/hw/s390x/tod.c b/hw/s390x/tod.c
new file mode 100644
index 000000000..fd5a36bf2
--- /dev/null
+++ b/hw/s390x/tod.c
@@ -0,0 +1,139 @@
+/*
+ * TOD (Time Of Day) clock
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/s390x/tod.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "sysemu/kvm.h"
+#include "sysemu/tcg.h"
+#include "sysemu/qtest.h"
+#include "migration/qemu-file-types.h"
+#include "migration/register.h"
+
+void s390_init_tod(void)
+{
+    Object *obj;
+
+    if (kvm_enabled()) {
+        obj = object_new(TYPE_KVM_S390_TOD);
+    } else if (tcg_enabled()) {
+        obj = object_new(TYPE_QEMU_S390_TOD);
+    } else if (qtest_enabled()) {
+        return;
+    } else {
+        error_report("current accelerator not handled in s390_init_tod!");
+        abort();
+    }
+    object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj);
+    object_unref(obj);
+
+    qdev_realize(DEVICE(obj), NULL, &error_fatal);
+}
+
+S390TODState *s390_get_todstate(void)
+{
+    static S390TODState *ts;
+
+    if (!ts) {
+        ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));
+    }
+
+    return ts;
+}
+
+#define S390_TOD_CLOCK_VALUE_MISSING    0x00
+#define S390_TOD_CLOCK_VALUE_PRESENT    0x01
+
+static void s390_tod_save(QEMUFile *f, void *opaque)
+{
+    S390TODState *td = opaque;
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    Error *err = NULL;
+    S390TOD tod;
+
+    tdc->get(td, &tod, &err);
+    if (err) {
+        warn_report_err(err);
+        error_printf("Guest clock will not be migrated "
+                     "which could cause the guest to hang.");
+        qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
+        return;
+    }
+
+    qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
+    qemu_put_byte(f, tod.high);
+    qemu_put_be64(f, tod.low);
+}
+
+static int s390_tod_load(QEMUFile *f, void *opaque, int version_id)
+{
+    S390TODState *td = opaque;
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    Error *err = NULL;
+    S390TOD tod;
+
+    if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
+        warn_report("Guest clock was not migrated. This could "
+                    "cause the guest to hang.");
+        return 0;
+    }
+
+    tod.high = qemu_get_byte(f);
+    tod.low = qemu_get_be64(f);
+
+    tdc->set(td, &tod, &err);
+    if (err) {
+        error_report_err(err);
+        return -1;
+    }
+    return 0;
+}
+
+static SaveVMHandlers savevm_tod = {
+    .save_state = s390_tod_save,
+    .load_state = s390_tod_load,
+};
+
+static void s390_tod_realize(DeviceState *dev, Error **errp)
+{
+    S390TODState *td = S390_TOD(dev);
+
+    /* Legacy migration interface */
+    register_savevm_live("todclock", 0, 1, &savevm_tod, td);
+}
+
+static void s390_tod_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->desc = "TOD (Time Of Day) Clock";
+    dc->realize = s390_tod_realize;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+
+    /* We only have one TOD clock in the system attached to the machine */
+    dc->user_creatable = false;
+}
+
+static TypeInfo s390_tod_info = {
+    .name = TYPE_S390_TOD,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(S390TODState),
+    .class_init = s390_tod_class_init,
+    .class_size = sizeof(S390TODClass),
+    .abstract = true,
+};
+
+static void register_types(void)
+{
+    type_register_static(&s390_tod_info);
+}
+type_init(register_types);