When instanciated, this object will connect to the given D-Bus
bus. During migration, it will take the data from org.qemu.VMState1
instances.
See documentation for further details.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
MAINTAINERS | 6 +
backends/Makefile.objs | 4 +
backends/dbus-vmstate.c | 332 ++++++++++++++++++++++++++++++
configure | 7 +
docs/interop/dbus-vmstate.rst | 63 ++++++
docs/interop/index.rst | 1 +
tests/Makefile.include | 18 +-
tests/dbus-vmstate-test.c | 371 ++++++++++++++++++++++++++++++++++
tests/dbus-vmstate1.xml | 12 ++
9 files changed, 813 insertions(+), 1 deletion(-)
create mode 100644 backends/dbus-vmstate.c
create mode 100644 docs/interop/dbus-vmstate.rst
create mode 100644 tests/dbus-vmstate-test.c
create mode 100644 tests/dbus-vmstate1.xml
diff --git a/MAINTAINERS b/MAINTAINERS
index d6de200453..d136bf4f4b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2143,6 +2143,12 @@ F: tests/migration-test.c
F: docs/devel/migration.rst
F: qapi/migration.json
+DBus VMState
+M: Marc-André Lureau <marcandre.lureau@redhat.com>
+S: Maintained
+F: backends/dbus-vmstate.c
+F: tests/dbus-vmstate*
+
Seccomp
M: Eduardo Otubo <otubo@redhat.com>
S: Supported
diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index 981e8e122f..dbbe12b225 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -17,3 +17,7 @@ endif
common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_VIRTIO)) += vhost-user.o
common-obj-$(CONFIG_LINUX) += hostmem-memfd.o
+
+common-obj-$(CONFIG_GIO) += dbus-vmstate.o
+dbus-vmstate.o-cflags = $(GIO_CFLAGS)
+dbus-vmstate.o-libs = $(GIO_LIBS)
diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c
new file mode 100644
index 0000000000..a9d9cac388
--- /dev/null
+++ b/backends/dbus-vmstate.c
@@ -0,0 +1,332 @@
+/*
+ * QEMU dbus-vmstate
+ *
+ * Copyright (C) 2019 Red Hat Inc
+ *
+ * Authors:
+ * Marc-André Lureau <marcandre.lureau@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 "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+#include "qapi/qmp/qerror.h"
+#include "migration/register.h"
+#include "migration/qemu-file-types.h"
+#include <gio/gio.h>
+
+typedef struct DBusVMState DBusVMState;
+typedef struct DBusVMStateClass DBusVMStateClass;
+
+#define TYPE_DBUS_VMSTATE "dbus-vmstate"
+#define DBUS_VMSTATE(obj) \
+ OBJECT_CHECK(DBusVMState, (obj), TYPE_DBUS_VMSTATE)
+#define DBUS_VMSTATE_GET_CLASS(obj) \
+ OBJECT_GET_CLASS(DBusVMStateClass, (obj), TYPE_DBUS_VMSTATE)
+#define DBUS_VMSTATE_CLASS(klass) \
+ OBJECT_CLASS_CHECK(DBusVMStateClass, (klass), TYPE_DBUS_VMSTATE)
+
+struct DBusVMStateClass {
+ ObjectClass parent_class;
+};
+
+struct DBusVMState {
+ Object parent;
+
+ GDBusConnection *bus;
+ GDBusProxy *proxy;
+ char *id;
+ char *dbus_addr;
+};
+
+static const GDBusPropertyInfo vmstate_property_info[] = {
+ { -1, (char *) "Id", (char *) "s",
+ G_DBUS_PROPERTY_INFO_FLAGS_READABLE, NULL },
+};
+
+static const GDBusPropertyInfo * const vmstate_property_info_pointers[] = {
+ &vmstate_property_info[0],
+ NULL
+};
+
+static const GDBusInterfaceInfo vmstate1_interface_info = {
+ -1,
+ (char *) "org.qemu.VMState1",
+ (GDBusMethodInfo **) NULL,
+ (GDBusSignalInfo **) NULL,
+ (GDBusPropertyInfo **) &vmstate_property_info_pointers,
+ NULL,
+};
+
+#define DBUS_VMSTATE_SIZE_LIMIT (1 << 20) /* 1mb */
+
+
+static char *
+get_idstr(DBusVMState *self)
+{
+ return g_strdup_printf("%s-%s", TYPE_DBUS_VMSTATE, self->id);
+}
+
+static char *
+dbus_proxy_get_id(GDBusProxy *proxy, GError **err)
+{
+ char *id = NULL;
+ GVariant *result = NULL;
+ size_t size;
+
+ result = g_dbus_proxy_get_cached_property(proxy, "Id");
+ if (!result) {
+ g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
+ "Failed to get Id property");
+ return NULL;
+ }
+
+ id = g_variant_dup_string(result, &size);
+ g_clear_pointer(&result, g_variant_unref);
+
+ if (size == 0 || size >= 256) {
+ g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
+ "Invalid Id property");
+ g_free(id);
+ return NULL;
+ }
+
+ return id;
+}
+
+static int
+dbus_load_state_proxy(GDBusProxy *proxy, const uint8_t *data, size_t size)
+{
+ GError *err = NULL;
+ GVariant *value, *result;
+ int ret = -1;
+
+ value = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
+ data, size, sizeof(char));
+ result = g_dbus_proxy_call_sync(proxy, "Load",
+ g_variant_new("(@ay)", value),
+ G_DBUS_CALL_FLAGS_NO_AUTO_START,
+ -1, NULL, &err);
+ if (!result) {
+ error_report("Failed to Load: %s", err->message);
+ goto end;
+ }
+
+ ret = 0;
+
+end:
+ g_clear_pointer(&result, g_variant_unref);
+ g_clear_error(&err);
+ return ret;
+}
+
+static int
+dbus_load_state(QEMUFile *f, void *opaque, int version_id)
+{
+ DBusVMState *self = DBUS_VMSTATE(opaque);
+ uint8_t *data = NULL;
+ int ret = -1;
+ char id[256];
+ unsigned int size;
+
+ if (qemu_get_counted_string(f, id) == 0) {
+ error_report("Invalid vmstate Id");
+ goto end;
+ }
+
+ if (g_strcmp0(id, self->id)) {
+ error_report("Invalid vmstate Id: %s != %s", id, self->id);
+ goto end;
+ }
+
+ size = qemu_get_be32(f);
+ if (size > DBUS_VMSTATE_SIZE_LIMIT) {
+ error_report("Invalid vmstate size: %u", size);
+ goto end;
+ }
+
+ data = g_malloc(size);
+ if (qemu_get_buffer(f, data, size) != size) {
+ error_report("Failed to read %u bytes", size);
+ goto end;
+ }
+
+ if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
+ error_report("Failed to restore Id '%s'", id);
+ goto end;
+ }
+
+ ret = 0;
+
+end:
+ g_clear_pointer(&data, g_free);
+ return ret;
+}
+
+static void
+dbus_save_state(QEMUFile *f, void *opaque)
+{
+ DBusVMState *self = DBUS_VMSTATE(opaque);
+ GVariant *result = NULL, *child = NULL;
+ const uint8_t *data;
+ size_t size;
+ GError *err = NULL;
+
+ result = g_dbus_proxy_call_sync(self->proxy, "Save",
+ NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
+ -1, NULL, &err);
+ if (!result) {
+ error_report("Failed to Save: %s", err->message);
+ g_clear_error(&err);
+ goto end;
+ }
+
+ child = g_variant_get_child_value(result, 0);
+ data = g_variant_get_fixed_array(child, &size, sizeof(char));
+ if (!data) {
+ error_report("Failed to Save: not a byte array");
+ goto end;
+ }
+ if (size > DBUS_VMSTATE_SIZE_LIMIT) {
+ error_report("Too much vmstate data to save: %zu", size);
+ goto end;
+ }
+
+ qemu_put_counted_string(f, self->id);
+ qemu_put_be32(f, size);
+ qemu_put_buffer(f, data, size);
+
+end:
+ g_clear_pointer(&child, g_variant_unref);
+ g_clear_pointer(&result, g_variant_unref);
+}
+
+static const SaveVMHandlers savevm_handlers = {
+ .save_state = dbus_save_state,
+ .load_state = dbus_load_state,
+};
+
+static void
+dbus_vmstate_complete(UserCreatable *uc, Error **errp)
+{
+ DBusVMState *self = DBUS_VMSTATE(uc);
+ GError *err = NULL;
+ GDBusConnection *bus = NULL;
+ GDBusProxy *proxy = NULL;
+ char *idstr = NULL;
+
+ if (!self->dbus_addr) {
+ error_setg(errp, QERR_MISSING_PARAMETER, "addr");
+ return;
+ }
+
+ bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
+ G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
+ NULL, NULL, &err);
+ if (err) {
+ error_setg(errp, "failed to connect to DBus: '%s'", err->message);
+ g_clear_error(&err);
+ return;
+ }
+
+ self->bus = bus;
+
+ proxy = g_dbus_proxy_new_sync(bus,
+ G_DBUS_PROXY_FLAGS_NONE,
+ (GDBusInterfaceInfo *) &vmstate1_interface_info,
+ NULL,
+ "/org/qemu/VMState1",
+ "org.qemu.VMState1",
+ NULL, &err);
+
+ if (err) {
+ error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
+ g_clear_error(&err);
+ return;
+ }
+
+ self->proxy = proxy;
+
+ self->id = dbus_proxy_get_id(proxy, &err);
+ if (!self->id) {
+ error_setg(errp, "failed to get DBus Id: '%s'", err->message);
+ g_clear_error(&err);
+ return;
+ }
+
+ idstr = get_idstr(self);
+ if (register_savevm_live(NULL, idstr, 0, 0,
+ &savevm_handlers, self) < 0) {
+ error_setg(errp, "Failed to register savevm handler");
+ }
+ g_free(idstr);
+}
+
+static void
+dbus_vmstate_finalize(Object *o)
+{
+ DBusVMState *self = DBUS_VMSTATE(o);
+ char *idstr = get_idstr(self);
+
+ unregister_savevm(NULL, idstr, self);
+
+ g_clear_object(&self->bus);
+ g_clear_object(&self->proxy);
+ g_free(self->dbus_addr);
+ g_free(self->id);
+ g_free(idstr);
+}
+
+static char *
+get_dbus_addr(Object *o, Error **errp)
+{
+ DBusVMState *self = DBUS_VMSTATE(o);
+
+ return g_strdup(self->dbus_addr);
+}
+
+static void
+set_dbus_addr(Object *o, const char *str, Error **errp)
+{
+ DBusVMState *self = DBUS_VMSTATE(o);
+
+ g_free(self->dbus_addr);
+ self->dbus_addr = g_strdup(str);
+}
+
+static void
+dbus_vmstate_class_init(ObjectClass *oc, void *data)
+{
+ UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+ ucc->complete = dbus_vmstate_complete;
+
+ object_class_property_add_str(oc, "addr",
+ get_dbus_addr, set_dbus_addr,
+ &error_abort);
+}
+
+static const TypeInfo dbus_vmstate_info = {
+ .name = TYPE_DBUS_VMSTATE,
+ .parent = TYPE_OBJECT,
+ .instance_size = sizeof(DBusVMState),
+ .instance_finalize = dbus_vmstate_finalize,
+ .class_size = sizeof(DBusVMStateClass),
+ .class_init = dbus_vmstate_class_init,
+ .interfaces = (InterfaceInfo[]) {
+ { TYPE_USER_CREATABLE },
+ { }
+ }
+};
+
+static void
+register_types(void)
+{
+ type_register_static(&dbus_vmstate_info);
+}
+
+type_init(register_types);
diff --git a/configure b/configure
index 714e7fb6a1..e5b34f5ca7 100755
--- a/configure
+++ b/configure
@@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
gio=yes
gio_cflags=$($pkg_config --cflags gio-2.0)
gio_libs=$($pkg_config --libs gio-2.0)
+ gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
else
gio=no
fi
+if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
+ gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
+ gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
+fi
+
# Sanity check that the current size_t matches the
# size that glib thinks it should be. This catches
# problems on multi-arch where people try to build
@@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
echo "CONFIG_GIO=y" >> $config_host_mak
echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
echo "GIO_LIBS=$gio_libs" >> $config_host_mak
+ echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
fi
echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
if test "$gnutls" = "yes" ; then
diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
new file mode 100644
index 0000000000..4a32a183fb
--- /dev/null
+++ b/docs/interop/dbus-vmstate.rst
@@ -0,0 +1,63 @@
+============
+DBus VMState
+============
+
+Introduction
+============
+
+Helper processes may have their state migrated with the help of
+QEMU "dbus-vmstate" objects.
+
+At this point, the connection to the helper is done in DBus
+peer-to-peer mode (no initial Hello, and no bus name for
+communication). The helper must be listening to the given address.
+
+Helper may save arbitrary data to be transferred in the migration
+stream and restored/loaded on destination.
+
+The data amount to be transferred is limited to 1Mb. The state must be
+saved quickly (a few seconds maximum). (DBus imposes a time limit on
+reply anyway, and migration would fail if the data isn't given quickly
+enough)
+
+Interface
+=========
+
+On /org/qemu/VMState1 object path:
+
+.. code:: xml
+
+ <interface name="org.qemu.VMState1">
+ <property name="Id" type="s" access="read"/>
+ <method name="Load">
+ <arg type="ay" name="data" direction="in"/>
+ </method>
+ <method name="Save">
+ <arg type="ay" name="data" direction="out"/>
+ </method>
+ </interface>
+
+"Id" property
+-------------
+
+A utf8 encoded string that identifies the helper uniquely.
+Must be <256 bytes.
+
+Load(in u8[] bytes) method
+--------------------------
+
+The method called on destination with the state to restore.
+
+The helper may be initially started in a waiting state (with
+an --incoming argument for example), and it may resume on load
+success.
+
+An error may be returned to the caller.
+
+Save(out u8[] bytes) method
+---------------------------
+
+The method called on the source to get the current state to be
+migrated. The helper should continue to run normally.
+
+An error may be returned to the caller.
diff --git a/docs/interop/index.rst b/docs/interop/index.rst
index b4bfcab417..6bb173cfa6 100644
--- a/docs/interop/index.rst
+++ b/docs/interop/index.rst
@@ -13,6 +13,7 @@ Contents:
:maxdepth: 2
bitmaps
+ dbus-vmstate
live-block-operations
pr-helper
vhost-user
diff --git a/tests/Makefile.include b/tests/Makefile.include
index fd7fdb8658..2c610086a7 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
-
+ifneq ($(GDBUS_CODEGEN),)
+check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
+endif
check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
check-qtest-i386-y += tests/fdc-test$(EXESUF)
check-qtest-i386-y += tests/ide-test$(EXESUF)
@@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
@mv tests/qapi-schema/doc-good-qapi-doc.texi $@
@rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
+tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
+tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
+ $(call quiet-command,$(GDBUS_CODEGEN) $< \
+ --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
+ "GEN","$(@:%-timestamp=%)")
+ @>$@
+
+tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
+tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
+
+tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
+
tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
@@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
+tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
@@ -1172,6 +1187,7 @@ check-clean:
rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
rm -f tests/test-qapi-gen-timestamp
+ rm -f tests/dbus-vmstate1-gen-timestamp
rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
clean: check-clean
diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
new file mode 100644
index 0000000000..45d44916d2
--- /dev/null
+++ b/tests/dbus-vmstate-test.c
@@ -0,0 +1,371 @@
+#include "qemu/osdep.h"
+#include <glib/gstdio.h>
+#include <gio/gio.h>
+#include "libqtest.h"
+#include "qemu-common.h"
+#include "dbus-vmstate1.h"
+
+static char *workdir;
+
+typedef struct TestServerId {
+ const char *name;
+ const char *data;
+ size_t size;
+} TestServerId;
+
+static const TestServerId idA = {
+ "idA", "I'am\0idA!", sizeof("I'am\0idA!")
+};
+
+static const TestServerId idB = {
+ "idB", "I'am\0idB!", sizeof("I'am\0idB!")
+};
+
+typedef struct TestServer {
+ const TestServerId *id;
+ bool save_called;
+ bool load_called;
+ GDBusObjectManagerServer *om;
+ GDBusServer *server;
+} TestServer;
+
+typedef struct Test {
+ bool migrate_fail;
+ TestServer srcA;
+ TestServer dstA;
+ TestServer srcB;
+ TestServer dstB;
+ GMainLoop *loop, *dbus_loop;
+ QTestState *src_qemu;
+} Test;
+
+GMutex mutex;
+GCond cond;
+
+static gboolean
+vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
+ const gchar *arg_data, gpointer user_data)
+{
+ TestServer *h = user_data;
+ GVariant *args, *var;
+ const uint8_t *data;
+ size_t size;
+
+ args = g_dbus_method_invocation_get_parameters(invocation);
+ var = g_variant_get_child_value(args, 0);
+ data = g_variant_get_fixed_array(var, &size, sizeof(char));
+ g_assert_cmpuint(size, ==, h->id->size);
+ g_assert(!memcmp(data, h->id->data, h->id->size));
+ h->load_called = true;
+ g_variant_unref(var);
+
+ g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
+ return TRUE;
+}
+
+static gboolean
+vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
+ gpointer user_data)
+{
+ TestServer *h = user_data;
+ GVariant *var;
+
+ var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
+ h->id->data, h->id->size, sizeof(char));
+ g_dbus_method_invocation_return_value(invocation,
+ g_variant_new("(@ay)", var));
+ h->save_called = true;
+
+ return TRUE;
+}
+
+static void
+connection_closed(GDBusConnection *connection,
+ gboolean remote_peer_vanished,
+ GError *Error,
+ gpointer user_data)
+{
+ TestServer *h = user_data;
+
+ g_clear_object(&h->om);
+ g_clear_object(&connection);
+}
+
+static GDBusObjectManagerServer *
+get_omserver(GDBusConnection *conn, gpointer user_data)
+{
+ TestServer *h = user_data;
+ GDBusObjectManagerServer *om;
+ GDBusObjectSkeleton *sk;
+ VMState1 *v;
+
+ om = g_dbus_object_manager_server_new("/org/qemu");
+ sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
+
+ v = vmstate1_skeleton_new();
+ g_object_set(v, "id", h->id->name, NULL);
+ g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
+ g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
+
+ g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
+ g_dbus_object_manager_server_export(om, sk);
+ g_dbus_object_manager_server_set_connection(om, conn);
+
+ g_clear_object(&v);
+ g_clear_object(&sk);
+
+ return om;
+}
+
+static gboolean
+on_new_connection(GDBusServer *server,
+ GDBusConnection *connection,
+ gpointer user_data)
+{
+ TestServer *h = user_data;
+
+ g_object_ref(connection);
+ g_signal_connect(connection, "closed",
+ G_CALLBACK(connection_closed), user_data);
+ h->om = get_omserver(connection, user_data);
+
+ return TRUE;
+}
+
+static gboolean
+allow_mechanism_cb(GDBusAuthObserver *observer,
+ const gchar *mechanism,
+ gpointer user_data)
+{
+ return g_strcmp0(mechanism, "EXTERNAL") == 0;
+}
+
+static gboolean
+authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
+ GIOStream *stream,
+ GCredentials *credentials,
+ gpointer user_data)
+{
+ gboolean authorized = FALSE;
+
+ if (credentials != NULL) {
+ GCredentials *own_credentials = g_credentials_new();
+
+ if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
+ authorized = TRUE;
+ }
+
+ g_clear_object(&own_credentials);
+ }
+
+ return authorized;
+}
+
+static GDBusServer *
+server_start(TestServer *h, const char *p, const TestServerId *id)
+{
+ GDBusAuthObserver *observer = NULL;
+ GDBusServer *server = NULL;
+ gchar *guid = NULL;
+ GError *error = NULL;
+ char *addr = NULL;
+
+ h->id = id;
+ addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
+ guid = g_dbus_generate_guid();
+ observer = g_dbus_auth_observer_new();
+ g_signal_connect(observer, "allow-mechanism",
+ G_CALLBACK(allow_mechanism_cb), h);
+ g_signal_connect(observer, "authorize-authenticated-peer",
+ G_CALLBACK(authorize_authenticated_peer_cb), h);
+
+ server = g_dbus_server_new_sync(addr,
+ G_DBUS_SERVER_FLAGS_NONE,
+ guid,
+ observer,
+ NULL, /* GCancellable */
+ &error);
+ g_dbus_server_start(server);
+ g_clear_object(&observer);
+ g_free(guid);
+
+ if (server == NULL) {
+ g_printerr("Error creating server at address %s: %s\n",
+ addr, error->message);
+ g_error_free(error);
+ return NULL;
+ }
+
+ g_signal_connect(server, "new-connection",
+ G_CALLBACK(on_new_connection), h);
+
+ g_free(addr);
+ return server;
+}
+
+
+static gpointer
+dbus_thread(gpointer p)
+{
+ Test *test = p;
+ GMainContext *context = g_main_context_new();
+ GMainLoop *loop = g_main_loop_new(context, FALSE);
+
+ g_main_context_push_thread_default(context);
+
+ g_mutex_lock(&mutex);
+ test->srcA.server = server_start(&test->srcA, "src", &idA);
+ test->srcB.server = server_start(&test->srcB, "src", &idB);
+ test->dstA.server = server_start(&test->dstA, "dst", &idA);
+ test->dstB.server = server_start(&test->dstB, "dst", &idB);
+ test->dbus_loop = loop;
+ g_cond_signal(&cond);
+ g_mutex_unlock(&mutex);
+
+ g_main_loop_run(loop);
+
+ g_main_loop_unref(loop);
+ g_main_context_unref(context);
+
+ g_mutex_lock(&mutex);
+ g_clear_object(&test->srcA.server);
+ g_clear_object(&test->srcB.server);
+ g_clear_object(&test->dstA.server);
+ g_clear_object(&test->dstB.server);
+ g_mutex_unlock(&mutex);
+
+ return NULL;
+}
+
+static gboolean
+wait_for_migration_complete(gpointer user_data)
+{
+ Test *test = user_data;
+ QDict *rsp_return;
+ bool stop = false;
+ const char *status;
+
+ qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
+ rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
+ status = qdict_get_str(rsp_return, "status");
+ if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
+ stop = true;
+ g_assert_cmpstr(status, ==,
+ test->migrate_fail ? "failed" : "completed");
+ }
+ qobject_unref(rsp_return);
+
+ if (stop) {
+ g_main_loop_quit(test->loop);
+ }
+ return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
+}
+
+static void migrate(QTestState *who, const char *uri)
+{
+ QDict *args, *rsp;
+
+ args = qdict_new();
+ qdict_put_str(args, "uri", uri);
+
+ rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
+
+ g_assert(qdict_haskey(rsp, "return"));
+ qobject_unref(rsp);
+}
+
+static void
+test_dbus_vmstate(Test *test)
+{
+ QTestState *src_qemu = NULL, *dst_qemu = NULL;
+ char *src_qemu_args = NULL, *dst_qemu_args = NULL;
+ char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
+ GThread *t = g_thread_new("dbus", dbus_thread, test);
+
+ g_mutex_lock(&mutex);
+ while (!test->dbus_loop) {
+ g_cond_wait(&cond, &mutex);
+ }
+
+ src_qemu_args =
+ g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
+ "-object dbus-vmstate,id=dvB,addr=%s",
+ g_dbus_server_get_client_address(test->srcA.server),
+ g_dbus_server_get_client_address(test->srcB.server));
+
+
+ dst_qemu_args =
+ g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
+ "-object dbus-vmstate,id=dvB,addr=%s "
+ "-incoming %s",
+ g_dbus_server_get_client_address(test->dstA.server),
+ g_dbus_server_get_client_address(test->dstB.server),
+ uri);
+
+ src_qemu = qtest_init(src_qemu_args);
+ dst_qemu = qtest_init(dst_qemu_args);
+
+ test->loop = g_main_loop_new(NULL, TRUE);
+
+ migrate(src_qemu, uri);
+ test->src_qemu = src_qemu;
+ g_timeout_add_seconds(1, wait_for_migration_complete, test);
+
+ g_main_loop_run(test->loop);
+ g_main_loop_unref(test->loop);
+
+ g_free(uri);
+ qtest_quit(dst_qemu);
+ qtest_quit(src_qemu);
+ g_free(dst_qemu_args);
+ g_free(src_qemu_args);
+
+ g_main_loop_quit(test->dbus_loop);
+ g_mutex_unlock(&mutex);
+
+ g_thread_join(t);
+}
+
+static void
+check_migrated(TestServer *s, TestServer *d)
+{
+ assert(s->save_called);
+ assert(!s->load_called);
+ assert(!d->save_called);
+ assert(d->load_called);
+}
+
+static void
+test_dbus_vmstate_migrate(void)
+{
+ Test test = { };
+
+ test_dbus_vmstate(&test);
+
+ check_migrated(&test.srcA, &test.dstA);
+ check_migrated(&test.srcB, &test.dstB);
+}
+
+int
+main(int argc, char **argv)
+{
+ GError *err = NULL;
+ int ret;
+
+ g_test_init(&argc, &argv, NULL);
+
+ workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
+ if (!workdir) {
+ g_error("Unable to create temporary dir: %s\n", err->message);
+ }
+
+ qtest_add_func("/dbus-vmstate/migrate",
+ test_dbus_vmstate_migrate);
+
+ ret = g_test_run();
+
+ rmdir(workdir);
+ g_free(workdir);
+
+ return ret;
+}
diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
new file mode 100644
index 0000000000..cc8563be4c
--- /dev/null
+++ b/tests/dbus-vmstate1.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
+ <interface name="org.qemu.VMState1">
+ <property name="Id" type="s" access="read"/>
+ <method name="Load">
+ <arg type="ay" name="data" direction="in"/>
+ </method>
+ <method name="Save">
+ <arg type="ay" name="data" direction="out"/>
+ </method>
+ </interface>
+</node>
--
2.23.0.rc1
* Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> When instanciated, this object will connect to the given D-Bus
> bus. During migration, it will take the data from org.qemu.VMState1
> instances.
>
> See documentation for further details.
I'll leave the main review to someone who understands the details of
DBUS, however from the migration side:
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
<snip>
> +
> +static int
> +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> +{
> + DBusVMState *self = DBUS_VMSTATE(opaque);
> + uint8_t *data = NULL;
> + int ret = -1;
> + char id[256];
> + unsigned int size;
Higher level question; do you actually need a separate ID, or does
the ID that's stored by the migration code in the section name
give you enough uniqueness?
> + if (qemu_get_counted_string(f, id) == 0) {
> + error_report("Invalid vmstate Id");
> + goto end;
I generally prefer to include something telling me where the error has
come from, just to make it easier to track down if I see the error in
a log; e.g. use __func__
> + }
> +
> + if (g_strcmp0(id, self->id)) {
> + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> + goto end;
> + }
> +
> + size = qemu_get_be32(f);
> + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> + error_report("Invalid vmstate size: %u", size);
> + goto end;
> + }
> +
> + data = g_malloc(size);
> + if (qemu_get_buffer(f, data, size) != size) {
> + error_report("Failed to read %u bytes", size);
> + goto end;
> + }
> +
> + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> + error_report("Failed to restore Id '%s'", id);
> + goto end;
> + }
> +
> + ret = 0;
> +
> +end:
> + g_clear_pointer(&data, g_free);
> + return ret;
> +}
> +
> +static void
> +dbus_save_state(QEMUFile *f, void *opaque)
> +{
> + DBusVMState *self = DBUS_VMSTATE(opaque);
> + GVariant *result = NULL, *child = NULL;
> + const uint8_t *data;
> + size_t size;
> + GError *err = NULL;
> +
> + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> + -1, NULL, &err);
> + if (!result) {
> + error_report("Failed to Save: %s", err->message);
> + g_clear_error(&err);
> + goto end;
> + }
> +
> + child = g_variant_get_child_value(result, 0);
> + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> + if (!data) {
> + error_report("Failed to Save: not a byte array");
> + goto end;
> + }
> + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> + error_report("Too much vmstate data to save: %zu", size);
> + goto end;
> + }
> +
> + qemu_put_counted_string(f, self->id);
> + qemu_put_be32(f, size);
> + qemu_put_buffer(f, data, size);
> +
> +end:
> + g_clear_pointer(&child, g_variant_unref);
> + g_clear_pointer(&result, g_variant_unref);
> +}
> +
> +static const SaveVMHandlers savevm_handlers = {
> + .save_state = dbus_save_state,
> + .load_state = dbus_load_state,
> +};
> +
> +static void
> +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(uc);
> + GError *err = NULL;
> + GDBusConnection *bus = NULL;
> + GDBusProxy *proxy = NULL;
> + char *idstr = NULL;
> +
> + if (!self->dbus_addr) {
> + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> + return;
> + }
> +
> + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> + NULL, NULL, &err);
> + if (err) {
> + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + self->bus = bus;
> +
> + proxy = g_dbus_proxy_new_sync(bus,
> + G_DBUS_PROXY_FLAGS_NONE,
> + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> + NULL,
> + "/org/qemu/VMState1",
> + "org.qemu.VMState1",
> + NULL, &err);
> +
> + if (err) {
> + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + self->proxy = proxy;
> +
> + self->id = dbus_proxy_get_id(proxy, &err);
> + if (!self->id) {
> + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + idstr = get_idstr(self);
> + if (register_savevm_live(NULL, idstr, 0, 0,
> + &savevm_handlers, self) < 0) {
> + error_setg(errp, "Failed to register savevm handler");
> + }
Can you try and avoid register_savevm_live if possible and just wire a
vmsd onto the class like most other devices? We don't have many
register_savevm_live calls, and I'd like to get them down to just the
iterative devices.
Dave
> + g_free(idstr);
> +}
> +
> +static void
> +dbus_vmstate_finalize(Object *o)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> + char *idstr = get_idstr(self);
> +
> + unregister_savevm(NULL, idstr, self);
> +
> + g_clear_object(&self->bus);
> + g_clear_object(&self->proxy);
> + g_free(self->dbus_addr);
> + g_free(self->id);
> + g_free(idstr);
> +}
> +
> +static char *
> +get_dbus_addr(Object *o, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> +
> + return g_strdup(self->dbus_addr);
> +}
> +
> +static void
> +set_dbus_addr(Object *o, const char *str, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> +
> + g_free(self->dbus_addr);
> + self->dbus_addr = g_strdup(str);
> +}
> +
> +static void
> +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> +{
> + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> +
> + ucc->complete = dbus_vmstate_complete;
> +
> + object_class_property_add_str(oc, "addr",
> + get_dbus_addr, set_dbus_addr,
> + &error_abort);
> +}
> +
> +static const TypeInfo dbus_vmstate_info = {
> + .name = TYPE_DBUS_VMSTATE,
> + .parent = TYPE_OBJECT,
> + .instance_size = sizeof(DBusVMState),
> + .instance_finalize = dbus_vmstate_finalize,
> + .class_size = sizeof(DBusVMStateClass),
> + .class_init = dbus_vmstate_class_init,
> + .interfaces = (InterfaceInfo[]) {
> + { TYPE_USER_CREATABLE },
> + { }
> + }
> +};
> +
> +static void
> +register_types(void)
> +{
> + type_register_static(&dbus_vmstate_info);
> +}
> +
> +type_init(register_types);
> diff --git a/configure b/configure
> index 714e7fb6a1..e5b34f5ca7 100755
> --- a/configure
> +++ b/configure
> @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> gio=yes
> gio_cflags=$($pkg_config --cflags gio-2.0)
> gio_libs=$($pkg_config --libs gio-2.0)
> + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> else
> gio=no
> fi
>
> +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> +fi
> +
> # Sanity check that the current size_t matches the
> # size that glib thinks it should be. This catches
> # problems on multi-arch where people try to build
> @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> echo "CONFIG_GIO=y" >> $config_host_mak
> echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> fi
> echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> if test "$gnutls" = "yes" ; then
> diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> new file mode 100644
> index 0000000000..4a32a183fb
> --- /dev/null
> +++ b/docs/interop/dbus-vmstate.rst
> @@ -0,0 +1,63 @@
> +============
> +DBus VMState
> +============
> +
> +Introduction
> +============
> +
> +Helper processes may have their state migrated with the help of
> +QEMU "dbus-vmstate" objects.
> +
> +At this point, the connection to the helper is done in DBus
> +peer-to-peer mode (no initial Hello, and no bus name for
> +communication). The helper must be listening to the given address.
> +
> +Helper may save arbitrary data to be transferred in the migration
> +stream and restored/loaded on destination.
> +
> +The data amount to be transferred is limited to 1Mb. The state must be
> +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> +reply anyway, and migration would fail if the data isn't given quickly
> +enough)
> +
> +Interface
> +=========
> +
> +On /org/qemu/VMState1 object path:
> +
> +.. code:: xml
> +
> + <interface name="org.qemu.VMState1">
> + <property name="Id" type="s" access="read"/>
> + <method name="Load">
> + <arg type="ay" name="data" direction="in"/>
> + </method>
> + <method name="Save">
> + <arg type="ay" name="data" direction="out"/>
> + </method>
> + </interface>
> +
> +"Id" property
> +-------------
> +
> +A utf8 encoded string that identifies the helper uniquely.
> +Must be <256 bytes.
> +
> +Load(in u8[] bytes) method
> +--------------------------
> +
> +The method called on destination with the state to restore.
> +
> +The helper may be initially started in a waiting state (with
> +an --incoming argument for example), and it may resume on load
> +success.
> +
> +An error may be returned to the caller.
> +
> +Save(out u8[] bytes) method
> +---------------------------
> +
> +The method called on the source to get the current state to be
> +migrated. The helper should continue to run normally.
> +
> +An error may be returned to the caller.
> diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> index b4bfcab417..6bb173cfa6 100644
> --- a/docs/interop/index.rst
> +++ b/docs/interop/index.rst
> @@ -13,6 +13,7 @@ Contents:
> :maxdepth: 2
>
> bitmaps
> + dbus-vmstate
> live-block-operations
> pr-helper
> vhost-user
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index fd7fdb8658..2c610086a7 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> -
> +ifneq ($(GDBUS_CODEGEN),)
> +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> +endif
> check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> check-qtest-i386-y += tests/fdc-test$(EXESUF)
> check-qtest-i386-y += tests/ide-test$(EXESUF)
> @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
>
> +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> + "GEN","$(@:%-timestamp=%)")
> + @>$@
> +
> +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> +
> +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> +
> tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> @@ -1172,6 +1187,7 @@ check-clean:
> rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> rm -f tests/test-qapi-gen-timestamp
> + rm -f tests/dbus-vmstate1-gen-timestamp
> rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
>
> clean: check-clean
> diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> new file mode 100644
> index 0000000000..45d44916d2
> --- /dev/null
> +++ b/tests/dbus-vmstate-test.c
> @@ -0,0 +1,371 @@
> +#include "qemu/osdep.h"
> +#include <glib/gstdio.h>
> +#include <gio/gio.h>
> +#include "libqtest.h"
> +#include "qemu-common.h"
> +#include "dbus-vmstate1.h"
> +
> +static char *workdir;
> +
> +typedef struct TestServerId {
> + const char *name;
> + const char *data;
> + size_t size;
> +} TestServerId;
> +
> +static const TestServerId idA = {
> + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> +};
> +
> +static const TestServerId idB = {
> + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> +};
> +
> +typedef struct TestServer {
> + const TestServerId *id;
> + bool save_called;
> + bool load_called;
> + GDBusObjectManagerServer *om;
> + GDBusServer *server;
> +} TestServer;
> +
> +typedef struct Test {
> + bool migrate_fail;
> + TestServer srcA;
> + TestServer dstA;
> + TestServer srcB;
> + TestServer dstB;
> + GMainLoop *loop, *dbus_loop;
> + QTestState *src_qemu;
> +} Test;
> +
> +GMutex mutex;
> +GCond cond;
> +
> +static gboolean
> +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> + const gchar *arg_data, gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GVariant *args, *var;
> + const uint8_t *data;
> + size_t size;
> +
> + args = g_dbus_method_invocation_get_parameters(invocation);
> + var = g_variant_get_child_value(args, 0);
> + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> + g_assert_cmpuint(size, ==, h->id->size);
> + g_assert(!memcmp(data, h->id->data, h->id->size));
> + h->load_called = true;
> + g_variant_unref(var);
> +
> + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> + return TRUE;
> +}
> +
> +static gboolean
> +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GVariant *var;
> +
> + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> + h->id->data, h->id->size, sizeof(char));
> + g_dbus_method_invocation_return_value(invocation,
> + g_variant_new("(@ay)", var));
> + h->save_called = true;
> +
> + return TRUE;
> +}
> +
> +static void
> +connection_closed(GDBusConnection *connection,
> + gboolean remote_peer_vanished,
> + GError *Error,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> +
> + g_clear_object(&h->om);
> + g_clear_object(&connection);
> +}
> +
> +static GDBusObjectManagerServer *
> +get_omserver(GDBusConnection *conn, gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GDBusObjectManagerServer *om;
> + GDBusObjectSkeleton *sk;
> + VMState1 *v;
> +
> + om = g_dbus_object_manager_server_new("/org/qemu");
> + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> +
> + v = vmstate1_skeleton_new();
> + g_object_set(v, "id", h->id->name, NULL);
> + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> +
> + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> + g_dbus_object_manager_server_export(om, sk);
> + g_dbus_object_manager_server_set_connection(om, conn);
> +
> + g_clear_object(&v);
> + g_clear_object(&sk);
> +
> + return om;
> +}
> +
> +static gboolean
> +on_new_connection(GDBusServer *server,
> + GDBusConnection *connection,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> +
> + g_object_ref(connection);
> + g_signal_connect(connection, "closed",
> + G_CALLBACK(connection_closed), user_data);
> + h->om = get_omserver(connection, user_data);
> +
> + return TRUE;
> +}
> +
> +static gboolean
> +allow_mechanism_cb(GDBusAuthObserver *observer,
> + const gchar *mechanism,
> + gpointer user_data)
> +{
> + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> +}
> +
> +static gboolean
> +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> + GIOStream *stream,
> + GCredentials *credentials,
> + gpointer user_data)
> +{
> + gboolean authorized = FALSE;
> +
> + if (credentials != NULL) {
> + GCredentials *own_credentials = g_credentials_new();
> +
> + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> + authorized = TRUE;
> + }
> +
> + g_clear_object(&own_credentials);
> + }
> +
> + return authorized;
> +}
> +
> +static GDBusServer *
> +server_start(TestServer *h, const char *p, const TestServerId *id)
> +{
> + GDBusAuthObserver *observer = NULL;
> + GDBusServer *server = NULL;
> + gchar *guid = NULL;
> + GError *error = NULL;
> + char *addr = NULL;
> +
> + h->id = id;
> + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> + guid = g_dbus_generate_guid();
> + observer = g_dbus_auth_observer_new();
> + g_signal_connect(observer, "allow-mechanism",
> + G_CALLBACK(allow_mechanism_cb), h);
> + g_signal_connect(observer, "authorize-authenticated-peer",
> + G_CALLBACK(authorize_authenticated_peer_cb), h);
> +
> + server = g_dbus_server_new_sync(addr,
> + G_DBUS_SERVER_FLAGS_NONE,
> + guid,
> + observer,
> + NULL, /* GCancellable */
> + &error);
> + g_dbus_server_start(server);
> + g_clear_object(&observer);
> + g_free(guid);
> +
> + if (server == NULL) {
> + g_printerr("Error creating server at address %s: %s\n",
> + addr, error->message);
> + g_error_free(error);
> + return NULL;
> + }
> +
> + g_signal_connect(server, "new-connection",
> + G_CALLBACK(on_new_connection), h);
> +
> + g_free(addr);
> + return server;
> +}
> +
> +
> +static gpointer
> +dbus_thread(gpointer p)
> +{
> + Test *test = p;
> + GMainContext *context = g_main_context_new();
> + GMainLoop *loop = g_main_loop_new(context, FALSE);
> +
> + g_main_context_push_thread_default(context);
> +
> + g_mutex_lock(&mutex);
> + test->srcA.server = server_start(&test->srcA, "src", &idA);
> + test->srcB.server = server_start(&test->srcB, "src", &idB);
> + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> + test->dbus_loop = loop;
> + g_cond_signal(&cond);
> + g_mutex_unlock(&mutex);
> +
> + g_main_loop_run(loop);
> +
> + g_main_loop_unref(loop);
> + g_main_context_unref(context);
> +
> + g_mutex_lock(&mutex);
> + g_clear_object(&test->srcA.server);
> + g_clear_object(&test->srcB.server);
> + g_clear_object(&test->dstA.server);
> + g_clear_object(&test->dstB.server);
> + g_mutex_unlock(&mutex);
> +
> + return NULL;
> +}
> +
> +static gboolean
> +wait_for_migration_complete(gpointer user_data)
> +{
> + Test *test = user_data;
> + QDict *rsp_return;
> + bool stop = false;
> + const char *status;
> +
> + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> + status = qdict_get_str(rsp_return, "status");
> + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> + stop = true;
> + g_assert_cmpstr(status, ==,
> + test->migrate_fail ? "failed" : "completed");
> + }
> + qobject_unref(rsp_return);
> +
> + if (stop) {
> + g_main_loop_quit(test->loop);
> + }
> + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> +}
> +
> +static void migrate(QTestState *who, const char *uri)
> +{
> + QDict *args, *rsp;
> +
> + args = qdict_new();
> + qdict_put_str(args, "uri", uri);
> +
> + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> +
> + g_assert(qdict_haskey(rsp, "return"));
> + qobject_unref(rsp);
> +}
> +
> +static void
> +test_dbus_vmstate(Test *test)
> +{
> + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> + GThread *t = g_thread_new("dbus", dbus_thread, test);
> +
> + g_mutex_lock(&mutex);
> + while (!test->dbus_loop) {
> + g_cond_wait(&cond, &mutex);
> + }
> +
> + src_qemu_args =
> + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> + "-object dbus-vmstate,id=dvB,addr=%s",
> + g_dbus_server_get_client_address(test->srcA.server),
> + g_dbus_server_get_client_address(test->srcB.server));
> +
> +
> + dst_qemu_args =
> + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> + "-object dbus-vmstate,id=dvB,addr=%s "
> + "-incoming %s",
> + g_dbus_server_get_client_address(test->dstA.server),
> + g_dbus_server_get_client_address(test->dstB.server),
> + uri);
> +
> + src_qemu = qtest_init(src_qemu_args);
> + dst_qemu = qtest_init(dst_qemu_args);
> +
> + test->loop = g_main_loop_new(NULL, TRUE);
> +
> + migrate(src_qemu, uri);
> + test->src_qemu = src_qemu;
> + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> +
> + g_main_loop_run(test->loop);
> + g_main_loop_unref(test->loop);
> +
> + g_free(uri);
> + qtest_quit(dst_qemu);
> + qtest_quit(src_qemu);
> + g_free(dst_qemu_args);
> + g_free(src_qemu_args);
> +
> + g_main_loop_quit(test->dbus_loop);
> + g_mutex_unlock(&mutex);
> +
> + g_thread_join(t);
> +}
> +
> +static void
> +check_migrated(TestServer *s, TestServer *d)
> +{
> + assert(s->save_called);
> + assert(!s->load_called);
> + assert(!d->save_called);
> + assert(d->load_called);
> +}
> +
> +static void
> +test_dbus_vmstate_migrate(void)
> +{
> + Test test = { };
> +
> + test_dbus_vmstate(&test);
> +
> + check_migrated(&test.srcA, &test.dstA);
> + check_migrated(&test.srcB, &test.dstB);
> +}
> +
> +int
> +main(int argc, char **argv)
> +{
> + GError *err = NULL;
> + int ret;
> +
> + g_test_init(&argc, &argv, NULL);
> +
> + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> + if (!workdir) {
> + g_error("Unable to create temporary dir: %s\n", err->message);
> + }
> +
> + qtest_add_func("/dbus-vmstate/migrate",
> + test_dbus_vmstate_migrate);
> +
> + ret = g_test_run();
> +
> + rmdir(workdir);
> + g_free(workdir);
> +
> + return ret;
> +}
> diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> new file mode 100644
> index 0000000000..cc8563be4c
> --- /dev/null
> +++ b/tests/dbus-vmstate1.xml
> @@ -0,0 +1,12 @@
> +<?xml version="1.0"?>
> +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> + <interface name="org.qemu.VMState1">
> + <property name="Id" type="s" access="read"/>
> + <method name="Load">
> + <arg type="ay" name="data" direction="in"/>
> + </method>
> + <method name="Save">
> + <arg type="ay" name="data" direction="out"/>
> + </method>
> + </interface>
> +</node>
> --
> 2.23.0.rc1
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Hi
On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
>
> * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > When instanciated, this object will connect to the given D-Bus
> > bus. During migration, it will take the data from org.qemu.VMState1
> > instances.
> >
> > See documentation for further details.
>
> I'll leave the main review to someone who understands the details of
> DBUS, however from the migration side:
>
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> <snip>
>
> > +
> > +static int
> > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > + uint8_t *data = NULL;
> > + int ret = -1;
> > + char id[256];
> > + unsigned int size;
>
> Higher level question; do you actually need a separate ID, or does
> the ID that's stored by the migration code in the section name
> give you enough uniqueness?
The ID stored in migration section name is based on the handler ID:
TYPE_DBUS_VMSTATE "-" handler_id
By design, handler_id must be unique (and documented as such).
Do you see a problem with that approach?
>
> > + if (qemu_get_counted_string(f, id) == 0) {
> > + error_report("Invalid vmstate Id");
> > + goto end;
>
> I generally prefer to include something telling me where the error has
> come from, just to make it easier to track down if I see the error in
> a log; e.g. use __func__
ok
>
> > + }
> > +
> > + if (g_strcmp0(id, self->id)) {
> > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > + goto end;
> > + }
> > +
> > + size = qemu_get_be32(f);
> > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > + error_report("Invalid vmstate size: %u", size);
> > + goto end;
> > + }
> > +
> > + data = g_malloc(size);
> > + if (qemu_get_buffer(f, data, size) != size) {
> > + error_report("Failed to read %u bytes", size);
> > + goto end;
> > + }
> > +
> > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > + error_report("Failed to restore Id '%s'", id);
> > + goto end;
> > + }
> > +
> > + ret = 0;
> > +
> > +end:
> > + g_clear_pointer(&data, g_free);
> > + return ret;
> > +}
> > +
> > +static void
> > +dbus_save_state(QEMUFile *f, void *opaque)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > + GVariant *result = NULL, *child = NULL;
> > + const uint8_t *data;
> > + size_t size;
> > + GError *err = NULL;
> > +
> > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > + -1, NULL, &err);
> > + if (!result) {
> > + error_report("Failed to Save: %s", err->message);
> > + g_clear_error(&err);
> > + goto end;
> > + }
> > +
> > + child = g_variant_get_child_value(result, 0);
> > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > + if (!data) {
> > + error_report("Failed to Save: not a byte array");
> > + goto end;
> > + }
> > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > + error_report("Too much vmstate data to save: %zu", size);
> > + goto end;
> > + }
> > +
> > + qemu_put_counted_string(f, self->id);
> > + qemu_put_be32(f, size);
> > + qemu_put_buffer(f, data, size);
> > +
> > +end:
> > + g_clear_pointer(&child, g_variant_unref);
> > + g_clear_pointer(&result, g_variant_unref);
> > +}
> > +
> > +static const SaveVMHandlers savevm_handlers = {
> > + .save_state = dbus_save_state,
> > + .load_state = dbus_load_state,
> > +};
> > +
> > +static void
> > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(uc);
> > + GError *err = NULL;
> > + GDBusConnection *bus = NULL;
> > + GDBusProxy *proxy = NULL;
> > + char *idstr = NULL;
> > +
> > + if (!self->dbus_addr) {
> > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > + return;
> > + }
> > +
> > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > + NULL, NULL, &err);
> > + if (err) {
> > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > + g_clear_error(&err);
> > + return;
> > + }
> > +
> > + self->bus = bus;
> > +
> > + proxy = g_dbus_proxy_new_sync(bus,
> > + G_DBUS_PROXY_FLAGS_NONE,
> > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > + NULL,
> > + "/org/qemu/VMState1",
> > + "org.qemu.VMState1",
> > + NULL, &err);
> > +
> > + if (err) {
> > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > + g_clear_error(&err);
> > + return;
> > + }
> > +
> > + self->proxy = proxy;
> > +
> > + self->id = dbus_proxy_get_id(proxy, &err);
> > + if (!self->id) {
> > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > + g_clear_error(&err);
> > + return;
> > + }
> > +
> > + idstr = get_idstr(self);
> > + if (register_savevm_live(NULL, idstr, 0, 0,
> > + &savevm_handlers, self) < 0) {
> > + error_setg(errp, "Failed to register savevm handler");
> > + }
>
> Can you try and avoid register_savevm_live if possible and just wire a
> vmsd onto the class like most other devices? We don't have many
> register_savevm_live calls, and I'd like to get them down to just the
> iterative devices.
Sure if I could, but it's not a device.
Perhaps we could have a qom interface for vmsd users? I can try that eventually.
thanks
> Dave
>
>
> > + g_free(idstr);
> > +}
> > +
> > +static void
> > +dbus_vmstate_finalize(Object *o)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(o);
> > + char *idstr = get_idstr(self);
> > +
> > + unregister_savevm(NULL, idstr, self);
> > +
> > + g_clear_object(&self->bus);
> > + g_clear_object(&self->proxy);
> > + g_free(self->dbus_addr);
> > + g_free(self->id);
> > + g_free(idstr);
> > +}
> > +
> > +static char *
> > +get_dbus_addr(Object *o, Error **errp)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(o);
> > +
> > + return g_strdup(self->dbus_addr);
> > +}
> > +
> > +static void
> > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > +{
> > + DBusVMState *self = DBUS_VMSTATE(o);
> > +
> > + g_free(self->dbus_addr);
> > + self->dbus_addr = g_strdup(str);
> > +}
> > +
> > +static void
> > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > +{
> > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > +
> > + ucc->complete = dbus_vmstate_complete;
> > +
> > + object_class_property_add_str(oc, "addr",
> > + get_dbus_addr, set_dbus_addr,
> > + &error_abort);
> > +}
> > +
> > +static const TypeInfo dbus_vmstate_info = {
> > + .name = TYPE_DBUS_VMSTATE,
> > + .parent = TYPE_OBJECT,
> > + .instance_size = sizeof(DBusVMState),
> > + .instance_finalize = dbus_vmstate_finalize,
> > + .class_size = sizeof(DBusVMStateClass),
> > + .class_init = dbus_vmstate_class_init,
> > + .interfaces = (InterfaceInfo[]) {
> > + { TYPE_USER_CREATABLE },
> > + { }
> > + }
> > +};
> > +
> > +static void
> > +register_types(void)
> > +{
> > + type_register_static(&dbus_vmstate_info);
> > +}
> > +
> > +type_init(register_types);
> > diff --git a/configure b/configure
> > index 714e7fb6a1..e5b34f5ca7 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > gio=yes
> > gio_cflags=$($pkg_config --cflags gio-2.0)
> > gio_libs=$($pkg_config --libs gio-2.0)
> > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > else
> > gio=no
> > fi
> >
> > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > +fi
> > +
> > # Sanity check that the current size_t matches the
> > # size that glib thinks it should be. This catches
> > # problems on multi-arch where people try to build
> > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > echo "CONFIG_GIO=y" >> $config_host_mak
> > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > fi
> > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > if test "$gnutls" = "yes" ; then
> > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > new file mode 100644
> > index 0000000000..4a32a183fb
> > --- /dev/null
> > +++ b/docs/interop/dbus-vmstate.rst
> > @@ -0,0 +1,63 @@
> > +============
> > +DBus VMState
> > +============
> > +
> > +Introduction
> > +============
> > +
> > +Helper processes may have their state migrated with the help of
> > +QEMU "dbus-vmstate" objects.
> > +
> > +At this point, the connection to the helper is done in DBus
> > +peer-to-peer mode (no initial Hello, and no bus name for
> > +communication). The helper must be listening to the given address.
> > +
> > +Helper may save arbitrary data to be transferred in the migration
> > +stream and restored/loaded on destination.
> > +
> > +The data amount to be transferred is limited to 1Mb. The state must be
> > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > +reply anyway, and migration would fail if the data isn't given quickly
> > +enough)
> > +
> > +Interface
> > +=========
> > +
> > +On /org/qemu/VMState1 object path:
> > +
> > +.. code:: xml
> > +
> > + <interface name="org.qemu.VMState1">
> > + <property name="Id" type="s" access="read"/>
> > + <method name="Load">
> > + <arg type="ay" name="data" direction="in"/>
> > + </method>
> > + <method name="Save">
> > + <arg type="ay" name="data" direction="out"/>
> > + </method>
> > + </interface>
> > +
> > +"Id" property
> > +-------------
> > +
> > +A utf8 encoded string that identifies the helper uniquely.
> > +Must be <256 bytes.
> > +
> > +Load(in u8[] bytes) method
> > +--------------------------
> > +
> > +The method called on destination with the state to restore.
> > +
> > +The helper may be initially started in a waiting state (with
> > +an --incoming argument for example), and it may resume on load
> > +success.
> > +
> > +An error may be returned to the caller.
> > +
> > +Save(out u8[] bytes) method
> > +---------------------------
> > +
> > +The method called on the source to get the current state to be
> > +migrated. The helper should continue to run normally.
> > +
> > +An error may be returned to the caller.
> > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > index b4bfcab417..6bb173cfa6 100644
> > --- a/docs/interop/index.rst
> > +++ b/docs/interop/index.rst
> > @@ -13,6 +13,7 @@ Contents:
> > :maxdepth: 2
> >
> > bitmaps
> > + dbus-vmstate
> > live-block-operations
> > pr-helper
> > vhost-user
> > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > index fd7fdb8658..2c610086a7 100644
> > --- a/tests/Makefile.include
> > +++ b/tests/Makefile.include
> > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > -
> > +ifneq ($(GDBUS_CODEGEN),)
> > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > +endif
> > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> >
> > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > + "GEN","$(@:%-timestamp=%)")
> > + @>$@
> > +
> > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > +
> > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > +
> > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > @@ -1172,6 +1187,7 @@ check-clean:
> > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > rm -f tests/test-qapi-gen-timestamp
> > + rm -f tests/dbus-vmstate1-gen-timestamp
> > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> >
> > clean: check-clean
> > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > new file mode 100644
> > index 0000000000..45d44916d2
> > --- /dev/null
> > +++ b/tests/dbus-vmstate-test.c
> > @@ -0,0 +1,371 @@
> > +#include "qemu/osdep.h"
> > +#include <glib/gstdio.h>
> > +#include <gio/gio.h>
> > +#include "libqtest.h"
> > +#include "qemu-common.h"
> > +#include "dbus-vmstate1.h"
> > +
> > +static char *workdir;
> > +
> > +typedef struct TestServerId {
> > + const char *name;
> > + const char *data;
> > + size_t size;
> > +} TestServerId;
> > +
> > +static const TestServerId idA = {
> > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > +};
> > +
> > +static const TestServerId idB = {
> > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > +};
> > +
> > +typedef struct TestServer {
> > + const TestServerId *id;
> > + bool save_called;
> > + bool load_called;
> > + GDBusObjectManagerServer *om;
> > + GDBusServer *server;
> > +} TestServer;
> > +
> > +typedef struct Test {
> > + bool migrate_fail;
> > + TestServer srcA;
> > + TestServer dstA;
> > + TestServer srcB;
> > + TestServer dstB;
> > + GMainLoop *loop, *dbus_loop;
> > + QTestState *src_qemu;
> > +} Test;
> > +
> > +GMutex mutex;
> > +GCond cond;
> > +
> > +static gboolean
> > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > + const gchar *arg_data, gpointer user_data)
> > +{
> > + TestServer *h = user_data;
> > + GVariant *args, *var;
> > + const uint8_t *data;
> > + size_t size;
> > +
> > + args = g_dbus_method_invocation_get_parameters(invocation);
> > + var = g_variant_get_child_value(args, 0);
> > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > + g_assert_cmpuint(size, ==, h->id->size);
> > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > + h->load_called = true;
> > + g_variant_unref(var);
> > +
> > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > + return TRUE;
> > +}
> > +
> > +static gboolean
> > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > + gpointer user_data)
> > +{
> > + TestServer *h = user_data;
> > + GVariant *var;
> > +
> > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > + h->id->data, h->id->size, sizeof(char));
> > + g_dbus_method_invocation_return_value(invocation,
> > + g_variant_new("(@ay)", var));
> > + h->save_called = true;
> > +
> > + return TRUE;
> > +}
> > +
> > +static void
> > +connection_closed(GDBusConnection *connection,
> > + gboolean remote_peer_vanished,
> > + GError *Error,
> > + gpointer user_data)
> > +{
> > + TestServer *h = user_data;
> > +
> > + g_clear_object(&h->om);
> > + g_clear_object(&connection);
> > +}
> > +
> > +static GDBusObjectManagerServer *
> > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > +{
> > + TestServer *h = user_data;
> > + GDBusObjectManagerServer *om;
> > + GDBusObjectSkeleton *sk;
> > + VMState1 *v;
> > +
> > + om = g_dbus_object_manager_server_new("/org/qemu");
> > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > +
> > + v = vmstate1_skeleton_new();
> > + g_object_set(v, "id", h->id->name, NULL);
> > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > +
> > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > + g_dbus_object_manager_server_export(om, sk);
> > + g_dbus_object_manager_server_set_connection(om, conn);
> > +
> > + g_clear_object(&v);
> > + g_clear_object(&sk);
> > +
> > + return om;
> > +}
> > +
> > +static gboolean
> > +on_new_connection(GDBusServer *server,
> > + GDBusConnection *connection,
> > + gpointer user_data)
> > +{
> > + TestServer *h = user_data;
> > +
> > + g_object_ref(connection);
> > + g_signal_connect(connection, "closed",
> > + G_CALLBACK(connection_closed), user_data);
> > + h->om = get_omserver(connection, user_data);
> > +
> > + return TRUE;
> > +}
> > +
> > +static gboolean
> > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > + const gchar *mechanism,
> > + gpointer user_data)
> > +{
> > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > +}
> > +
> > +static gboolean
> > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > + GIOStream *stream,
> > + GCredentials *credentials,
> > + gpointer user_data)
> > +{
> > + gboolean authorized = FALSE;
> > +
> > + if (credentials != NULL) {
> > + GCredentials *own_credentials = g_credentials_new();
> > +
> > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > + authorized = TRUE;
> > + }
> > +
> > + g_clear_object(&own_credentials);
> > + }
> > +
> > + return authorized;
> > +}
> > +
> > +static GDBusServer *
> > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > +{
> > + GDBusAuthObserver *observer = NULL;
> > + GDBusServer *server = NULL;
> > + gchar *guid = NULL;
> > + GError *error = NULL;
> > + char *addr = NULL;
> > +
> > + h->id = id;
> > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > + guid = g_dbus_generate_guid();
> > + observer = g_dbus_auth_observer_new();
> > + g_signal_connect(observer, "allow-mechanism",
> > + G_CALLBACK(allow_mechanism_cb), h);
> > + g_signal_connect(observer, "authorize-authenticated-peer",
> > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > +
> > + server = g_dbus_server_new_sync(addr,
> > + G_DBUS_SERVER_FLAGS_NONE,
> > + guid,
> > + observer,
> > + NULL, /* GCancellable */
> > + &error);
> > + g_dbus_server_start(server);
> > + g_clear_object(&observer);
> > + g_free(guid);
> > +
> > + if (server == NULL) {
> > + g_printerr("Error creating server at address %s: %s\n",
> > + addr, error->message);
> > + g_error_free(error);
> > + return NULL;
> > + }
> > +
> > + g_signal_connect(server, "new-connection",
> > + G_CALLBACK(on_new_connection), h);
> > +
> > + g_free(addr);
> > + return server;
> > +}
> > +
> > +
> > +static gpointer
> > +dbus_thread(gpointer p)
> > +{
> > + Test *test = p;
> > + GMainContext *context = g_main_context_new();
> > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > +
> > + g_main_context_push_thread_default(context);
> > +
> > + g_mutex_lock(&mutex);
> > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > + test->dbus_loop = loop;
> > + g_cond_signal(&cond);
> > + g_mutex_unlock(&mutex);
> > +
> > + g_main_loop_run(loop);
> > +
> > + g_main_loop_unref(loop);
> > + g_main_context_unref(context);
> > +
> > + g_mutex_lock(&mutex);
> > + g_clear_object(&test->srcA.server);
> > + g_clear_object(&test->srcB.server);
> > + g_clear_object(&test->dstA.server);
> > + g_clear_object(&test->dstB.server);
> > + g_mutex_unlock(&mutex);
> > +
> > + return NULL;
> > +}
> > +
> > +static gboolean
> > +wait_for_migration_complete(gpointer user_data)
> > +{
> > + Test *test = user_data;
> > + QDict *rsp_return;
> > + bool stop = false;
> > + const char *status;
> > +
> > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > + status = qdict_get_str(rsp_return, "status");
> > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > + stop = true;
> > + g_assert_cmpstr(status, ==,
> > + test->migrate_fail ? "failed" : "completed");
> > + }
> > + qobject_unref(rsp_return);
> > +
> > + if (stop) {
> > + g_main_loop_quit(test->loop);
> > + }
> > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > +}
> > +
> > +static void migrate(QTestState *who, const char *uri)
> > +{
> > + QDict *args, *rsp;
> > +
> > + args = qdict_new();
> > + qdict_put_str(args, "uri", uri);
> > +
> > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > +
> > + g_assert(qdict_haskey(rsp, "return"));
> > + qobject_unref(rsp);
> > +}
> > +
> > +static void
> > +test_dbus_vmstate(Test *test)
> > +{
> > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > +
> > + g_mutex_lock(&mutex);
> > + while (!test->dbus_loop) {
> > + g_cond_wait(&cond, &mutex);
> > + }
> > +
> > + src_qemu_args =
> > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > + "-object dbus-vmstate,id=dvB,addr=%s",
> > + g_dbus_server_get_client_address(test->srcA.server),
> > + g_dbus_server_get_client_address(test->srcB.server));
> > +
> > +
> > + dst_qemu_args =
> > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > + "-object dbus-vmstate,id=dvB,addr=%s "
> > + "-incoming %s",
> > + g_dbus_server_get_client_address(test->dstA.server),
> > + g_dbus_server_get_client_address(test->dstB.server),
> > + uri);
> > +
> > + src_qemu = qtest_init(src_qemu_args);
> > + dst_qemu = qtest_init(dst_qemu_args);
> > +
> > + test->loop = g_main_loop_new(NULL, TRUE);
> > +
> > + migrate(src_qemu, uri);
> > + test->src_qemu = src_qemu;
> > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > +
> > + g_main_loop_run(test->loop);
> > + g_main_loop_unref(test->loop);
> > +
> > + g_free(uri);
> > + qtest_quit(dst_qemu);
> > + qtest_quit(src_qemu);
> > + g_free(dst_qemu_args);
> > + g_free(src_qemu_args);
> > +
> > + g_main_loop_quit(test->dbus_loop);
> > + g_mutex_unlock(&mutex);
> > +
> > + g_thread_join(t);
> > +}
> > +
> > +static void
> > +check_migrated(TestServer *s, TestServer *d)
> > +{
> > + assert(s->save_called);
> > + assert(!s->load_called);
> > + assert(!d->save_called);
> > + assert(d->load_called);
> > +}
> > +
> > +static void
> > +test_dbus_vmstate_migrate(void)
> > +{
> > + Test test = { };
> > +
> > + test_dbus_vmstate(&test);
> > +
> > + check_migrated(&test.srcA, &test.dstA);
> > + check_migrated(&test.srcB, &test.dstB);
> > +}
> > +
> > +int
> > +main(int argc, char **argv)
> > +{
> > + GError *err = NULL;
> > + int ret;
> > +
> > + g_test_init(&argc, &argv, NULL);
> > +
> > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > + if (!workdir) {
> > + g_error("Unable to create temporary dir: %s\n", err->message);
> > + }
> > +
> > + qtest_add_func("/dbus-vmstate/migrate",
> > + test_dbus_vmstate_migrate);
> > +
> > + ret = g_test_run();
> > +
> > + rmdir(workdir);
> > + g_free(workdir);
> > +
> > + return ret;
> > +}
> > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > new file mode 100644
> > index 0000000000..cc8563be4c
> > --- /dev/null
> > +++ b/tests/dbus-vmstate1.xml
> > @@ -0,0 +1,12 @@
> > +<?xml version="1.0"?>
> > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > + <interface name="org.qemu.VMState1">
> > + <property name="Id" type="s" access="read"/>
> > + <method name="Load">
> > + <arg type="ay" name="data" direction="in"/>
> > + </method>
> > + <method name="Save">
> > + <arg type="ay" name="data" direction="out"/>
> > + </method>
> > + </interface>
> > +</node>
> > --
> > 2.23.0.rc1
> >
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> Hi
>
> On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> >
> > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > When instanciated, this object will connect to the given D-Bus
> > > bus. During migration, it will take the data from org.qemu.VMState1
> > > instances.
> > >
> > > See documentation for further details.
> >
> > I'll leave the main review to someone who understands the details of
> > DBUS, however from the migration side:
> >
> > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> >
> > <snip>
> >
> > > +
> > > +static int
> > > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > + uint8_t *data = NULL;
> > > + int ret = -1;
> > > + char id[256];
> > > + unsigned int size;
> >
> > Higher level question; do you actually need a separate ID, or does
> > the ID that's stored by the migration code in the section name
> > give you enough uniqueness?
>
>
> The ID stored in migration section name is based on the handler ID:
> TYPE_DBUS_VMSTATE "-" handler_id
>
> By design, handler_id must be unique (and documented as such).
>
> Do you see a problem with that approach?
OK, so if that's unique, why do you need an 'id' stored here?
> >
> > > + if (qemu_get_counted_string(f, id) == 0) {
> > > + error_report("Invalid vmstate Id");
> > > + goto end;
> >
> > I generally prefer to include something telling me where the error has
> > come from, just to make it easier to track down if I see the error in
> > a log; e.g. use __func__
>
> ok
>
> >
> > > + }
> > > +
> > > + if (g_strcmp0(id, self->id)) {
> > > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > > + goto end;
> > > + }
> > > +
> > > + size = qemu_get_be32(f);
> > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > + error_report("Invalid vmstate size: %u", size);
> > > + goto end;
> > > + }
> > > +
> > > + data = g_malloc(size);
> > > + if (qemu_get_buffer(f, data, size) != size) {
> > > + error_report("Failed to read %u bytes", size);
> > > + goto end;
> > > + }
> > > +
> > > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > > + error_report("Failed to restore Id '%s'", id);
> > > + goto end;
> > > + }
> > > +
> > > + ret = 0;
> > > +
> > > +end:
> > > + g_clear_pointer(&data, g_free);
> > > + return ret;
> > > +}
> > > +
> > > +static void
> > > +dbus_save_state(QEMUFile *f, void *opaque)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > + GVariant *result = NULL, *child = NULL;
> > > + const uint8_t *data;
> > > + size_t size;
> > > + GError *err = NULL;
> > > +
> > > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > > + -1, NULL, &err);
> > > + if (!result) {
> > > + error_report("Failed to Save: %s", err->message);
> > > + g_clear_error(&err);
> > > + goto end;
> > > + }
> > > +
> > > + child = g_variant_get_child_value(result, 0);
> > > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > > + if (!data) {
> > > + error_report("Failed to Save: not a byte array");
> > > + goto end;
> > > + }
> > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > + error_report("Too much vmstate data to save: %zu", size);
> > > + goto end;
> > > + }
> > > +
> > > + qemu_put_counted_string(f, self->id);
> > > + qemu_put_be32(f, size);
> > > + qemu_put_buffer(f, data, size);
> > > +
> > > +end:
> > > + g_clear_pointer(&child, g_variant_unref);
> > > + g_clear_pointer(&result, g_variant_unref);
> > > +}
> > > +
> > > +static const SaveVMHandlers savevm_handlers = {
> > > + .save_state = dbus_save_state,
> > > + .load_state = dbus_load_state,
> > > +};
> > > +
> > > +static void
> > > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(uc);
> > > + GError *err = NULL;
> > > + GDBusConnection *bus = NULL;
> > > + GDBusProxy *proxy = NULL;
> > > + char *idstr = NULL;
> > > +
> > > + if (!self->dbus_addr) {
> > > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > > + return;
> > > + }
> > > +
> > > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > > + NULL, NULL, &err);
> > > + if (err) {
> > > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > > + g_clear_error(&err);
> > > + return;
> > > + }
> > > +
> > > + self->bus = bus;
> > > +
> > > + proxy = g_dbus_proxy_new_sync(bus,
> > > + G_DBUS_PROXY_FLAGS_NONE,
> > > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > > + NULL,
> > > + "/org/qemu/VMState1",
> > > + "org.qemu.VMState1",
> > > + NULL, &err);
> > > +
> > > + if (err) {
> > > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > > + g_clear_error(&err);
> > > + return;
> > > + }
> > > +
> > > + self->proxy = proxy;
> > > +
> > > + self->id = dbus_proxy_get_id(proxy, &err);
> > > + if (!self->id) {
> > > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > > + g_clear_error(&err);
> > > + return;
> > > + }
> > > +
> > > + idstr = get_idstr(self);
> > > + if (register_savevm_live(NULL, idstr, 0, 0,
> > > + &savevm_handlers, self) < 0) {
> > > + error_setg(errp, "Failed to register savevm handler");
> > > + }
> >
> > Can you try and avoid register_savevm_live if possible and just wire a
> > vmsd onto the class like most other devices? We don't have many
> > register_savevm_live calls, and I'd like to get them down to just the
> > iterative devices.
>
> Sure if I could, but it's not a device.
>
> Perhaps we could have a qom interface for vmsd users? I can try that eventually.
Hmm, why isn't it a device?
Dave
> thanks
>
> > Dave
> >
> >
> > > + g_free(idstr);
> > > +}
> > > +
> > > +static void
> > > +dbus_vmstate_finalize(Object *o)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > + char *idstr = get_idstr(self);
> > > +
> > > + unregister_savevm(NULL, idstr, self);
> > > +
> > > + g_clear_object(&self->bus);
> > > + g_clear_object(&self->proxy);
> > > + g_free(self->dbus_addr);
> > > + g_free(self->id);
> > > + g_free(idstr);
> > > +}
> > > +
> > > +static char *
> > > +get_dbus_addr(Object *o, Error **errp)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > +
> > > + return g_strdup(self->dbus_addr);
> > > +}
> > > +
> > > +static void
> > > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > > +{
> > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > +
> > > + g_free(self->dbus_addr);
> > > + self->dbus_addr = g_strdup(str);
> > > +}
> > > +
> > > +static void
> > > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > > +{
> > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > > +
> > > + ucc->complete = dbus_vmstate_complete;
> > > +
> > > + object_class_property_add_str(oc, "addr",
> > > + get_dbus_addr, set_dbus_addr,
> > > + &error_abort);
> > > +}
> > > +
> > > +static const TypeInfo dbus_vmstate_info = {
> > > + .name = TYPE_DBUS_VMSTATE,
> > > + .parent = TYPE_OBJECT,
> > > + .instance_size = sizeof(DBusVMState),
> > > + .instance_finalize = dbus_vmstate_finalize,
> > > + .class_size = sizeof(DBusVMStateClass),
> > > + .class_init = dbus_vmstate_class_init,
> > > + .interfaces = (InterfaceInfo[]) {
> > > + { TYPE_USER_CREATABLE },
> > > + { }
> > > + }
> > > +};
> > > +
> > > +static void
> > > +register_types(void)
> > > +{
> > > + type_register_static(&dbus_vmstate_info);
> > > +}
> > > +
> > > +type_init(register_types);
> > > diff --git a/configure b/configure
> > > index 714e7fb6a1..e5b34f5ca7 100755
> > > --- a/configure
> > > +++ b/configure
> > > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > > gio=yes
> > > gio_cflags=$($pkg_config --cflags gio-2.0)
> > > gio_libs=$($pkg_config --libs gio-2.0)
> > > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > > else
> > > gio=no
> > > fi
> > >
> > > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > > +fi
> > > +
> > > # Sanity check that the current size_t matches the
> > > # size that glib thinks it should be. This catches
> > > # problems on multi-arch where people try to build
> > > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > > echo "CONFIG_GIO=y" >> $config_host_mak
> > > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > > fi
> > > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > > if test "$gnutls" = "yes" ; then
> > > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > > new file mode 100644
> > > index 0000000000..4a32a183fb
> > > --- /dev/null
> > > +++ b/docs/interop/dbus-vmstate.rst
> > > @@ -0,0 +1,63 @@
> > > +============
> > > +DBus VMState
> > > +============
> > > +
> > > +Introduction
> > > +============
> > > +
> > > +Helper processes may have their state migrated with the help of
> > > +QEMU "dbus-vmstate" objects.
> > > +
> > > +At this point, the connection to the helper is done in DBus
> > > +peer-to-peer mode (no initial Hello, and no bus name for
> > > +communication). The helper must be listening to the given address.
> > > +
> > > +Helper may save arbitrary data to be transferred in the migration
> > > +stream and restored/loaded on destination.
> > > +
> > > +The data amount to be transferred is limited to 1Mb. The state must be
> > > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > > +reply anyway, and migration would fail if the data isn't given quickly
> > > +enough)
> > > +
> > > +Interface
> > > +=========
> > > +
> > > +On /org/qemu/VMState1 object path:
> > > +
> > > +.. code:: xml
> > > +
> > > + <interface name="org.qemu.VMState1">
> > > + <property name="Id" type="s" access="read"/>
> > > + <method name="Load">
> > > + <arg type="ay" name="data" direction="in"/>
> > > + </method>
> > > + <method name="Save">
> > > + <arg type="ay" name="data" direction="out"/>
> > > + </method>
> > > + </interface>
> > > +
> > > +"Id" property
> > > +-------------
> > > +
> > > +A utf8 encoded string that identifies the helper uniquely.
> > > +Must be <256 bytes.
> > > +
> > > +Load(in u8[] bytes) method
> > > +--------------------------
> > > +
> > > +The method called on destination with the state to restore.
> > > +
> > > +The helper may be initially started in a waiting state (with
> > > +an --incoming argument for example), and it may resume on load
> > > +success.
> > > +
> > > +An error may be returned to the caller.
> > > +
> > > +Save(out u8[] bytes) method
> > > +---------------------------
> > > +
> > > +The method called on the source to get the current state to be
> > > +migrated. The helper should continue to run normally.
> > > +
> > > +An error may be returned to the caller.
> > > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > > index b4bfcab417..6bb173cfa6 100644
> > > --- a/docs/interop/index.rst
> > > +++ b/docs/interop/index.rst
> > > @@ -13,6 +13,7 @@ Contents:
> > > :maxdepth: 2
> > >
> > > bitmaps
> > > + dbus-vmstate
> > > live-block-operations
> > > pr-helper
> > > vhost-user
> > > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > > index fd7fdb8658..2c610086a7 100644
> > > --- a/tests/Makefile.include
> > > +++ b/tests/Makefile.include
> > > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > > -
> > > +ifneq ($(GDBUS_CODEGEN),)
> > > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > > +endif
> > > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> > >
> > > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > > + "GEN","$(@:%-timestamp=%)")
> > > + @>$@
> > > +
> > > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > > +
> > > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > > +
> > > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > > @@ -1172,6 +1187,7 @@ check-clean:
> > > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > > rm -f tests/test-qapi-gen-timestamp
> > > + rm -f tests/dbus-vmstate1-gen-timestamp
> > > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> > >
> > > clean: check-clean
> > > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > > new file mode 100644
> > > index 0000000000..45d44916d2
> > > --- /dev/null
> > > +++ b/tests/dbus-vmstate-test.c
> > > @@ -0,0 +1,371 @@
> > > +#include "qemu/osdep.h"
> > > +#include <glib/gstdio.h>
> > > +#include <gio/gio.h>
> > > +#include "libqtest.h"
> > > +#include "qemu-common.h"
> > > +#include "dbus-vmstate1.h"
> > > +
> > > +static char *workdir;
> > > +
> > > +typedef struct TestServerId {
> > > + const char *name;
> > > + const char *data;
> > > + size_t size;
> > > +} TestServerId;
> > > +
> > > +static const TestServerId idA = {
> > > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > > +};
> > > +
> > > +static const TestServerId idB = {
> > > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > > +};
> > > +
> > > +typedef struct TestServer {
> > > + const TestServerId *id;
> > > + bool save_called;
> > > + bool load_called;
> > > + GDBusObjectManagerServer *om;
> > > + GDBusServer *server;
> > > +} TestServer;
> > > +
> > > +typedef struct Test {
> > > + bool migrate_fail;
> > > + TestServer srcA;
> > > + TestServer dstA;
> > > + TestServer srcB;
> > > + TestServer dstB;
> > > + GMainLoop *loop, *dbus_loop;
> > > + QTestState *src_qemu;
> > > +} Test;
> > > +
> > > +GMutex mutex;
> > > +GCond cond;
> > > +
> > > +static gboolean
> > > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > > + const gchar *arg_data, gpointer user_data)
> > > +{
> > > + TestServer *h = user_data;
> > > + GVariant *args, *var;
> > > + const uint8_t *data;
> > > + size_t size;
> > > +
> > > + args = g_dbus_method_invocation_get_parameters(invocation);
> > > + var = g_variant_get_child_value(args, 0);
> > > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > > + g_assert_cmpuint(size, ==, h->id->size);
> > > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > > + h->load_called = true;
> > > + g_variant_unref(var);
> > > +
> > > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > > + return TRUE;
> > > +}
> > > +
> > > +static gboolean
> > > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > > + gpointer user_data)
> > > +{
> > > + TestServer *h = user_data;
> > > + GVariant *var;
> > > +
> > > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > > + h->id->data, h->id->size, sizeof(char));
> > > + g_dbus_method_invocation_return_value(invocation,
> > > + g_variant_new("(@ay)", var));
> > > + h->save_called = true;
> > > +
> > > + return TRUE;
> > > +}
> > > +
> > > +static void
> > > +connection_closed(GDBusConnection *connection,
> > > + gboolean remote_peer_vanished,
> > > + GError *Error,
> > > + gpointer user_data)
> > > +{
> > > + TestServer *h = user_data;
> > > +
> > > + g_clear_object(&h->om);
> > > + g_clear_object(&connection);
> > > +}
> > > +
> > > +static GDBusObjectManagerServer *
> > > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > > +{
> > > + TestServer *h = user_data;
> > > + GDBusObjectManagerServer *om;
> > > + GDBusObjectSkeleton *sk;
> > > + VMState1 *v;
> > > +
> > > + om = g_dbus_object_manager_server_new("/org/qemu");
> > > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > > +
> > > + v = vmstate1_skeleton_new();
> > > + g_object_set(v, "id", h->id->name, NULL);
> > > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > > +
> > > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > > + g_dbus_object_manager_server_export(om, sk);
> > > + g_dbus_object_manager_server_set_connection(om, conn);
> > > +
> > > + g_clear_object(&v);
> > > + g_clear_object(&sk);
> > > +
> > > + return om;
> > > +}
> > > +
> > > +static gboolean
> > > +on_new_connection(GDBusServer *server,
> > > + GDBusConnection *connection,
> > > + gpointer user_data)
> > > +{
> > > + TestServer *h = user_data;
> > > +
> > > + g_object_ref(connection);
> > > + g_signal_connect(connection, "closed",
> > > + G_CALLBACK(connection_closed), user_data);
> > > + h->om = get_omserver(connection, user_data);
> > > +
> > > + return TRUE;
> > > +}
> > > +
> > > +static gboolean
> > > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > > + const gchar *mechanism,
> > > + gpointer user_data)
> > > +{
> > > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > > +}
> > > +
> > > +static gboolean
> > > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > > + GIOStream *stream,
> > > + GCredentials *credentials,
> > > + gpointer user_data)
> > > +{
> > > + gboolean authorized = FALSE;
> > > +
> > > + if (credentials != NULL) {
> > > + GCredentials *own_credentials = g_credentials_new();
> > > +
> > > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > > + authorized = TRUE;
> > > + }
> > > +
> > > + g_clear_object(&own_credentials);
> > > + }
> > > +
> > > + return authorized;
> > > +}
> > > +
> > > +static GDBusServer *
> > > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > > +{
> > > + GDBusAuthObserver *observer = NULL;
> > > + GDBusServer *server = NULL;
> > > + gchar *guid = NULL;
> > > + GError *error = NULL;
> > > + char *addr = NULL;
> > > +
> > > + h->id = id;
> > > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > > + guid = g_dbus_generate_guid();
> > > + observer = g_dbus_auth_observer_new();
> > > + g_signal_connect(observer, "allow-mechanism",
> > > + G_CALLBACK(allow_mechanism_cb), h);
> > > + g_signal_connect(observer, "authorize-authenticated-peer",
> > > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > > +
> > > + server = g_dbus_server_new_sync(addr,
> > > + G_DBUS_SERVER_FLAGS_NONE,
> > > + guid,
> > > + observer,
> > > + NULL, /* GCancellable */
> > > + &error);
> > > + g_dbus_server_start(server);
> > > + g_clear_object(&observer);
> > > + g_free(guid);
> > > +
> > > + if (server == NULL) {
> > > + g_printerr("Error creating server at address %s: %s\n",
> > > + addr, error->message);
> > > + g_error_free(error);
> > > + return NULL;
> > > + }
> > > +
> > > + g_signal_connect(server, "new-connection",
> > > + G_CALLBACK(on_new_connection), h);
> > > +
> > > + g_free(addr);
> > > + return server;
> > > +}
> > > +
> > > +
> > > +static gpointer
> > > +dbus_thread(gpointer p)
> > > +{
> > > + Test *test = p;
> > > + GMainContext *context = g_main_context_new();
> > > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > > +
> > > + g_main_context_push_thread_default(context);
> > > +
> > > + g_mutex_lock(&mutex);
> > > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > > + test->dbus_loop = loop;
> > > + g_cond_signal(&cond);
> > > + g_mutex_unlock(&mutex);
> > > +
> > > + g_main_loop_run(loop);
> > > +
> > > + g_main_loop_unref(loop);
> > > + g_main_context_unref(context);
> > > +
> > > + g_mutex_lock(&mutex);
> > > + g_clear_object(&test->srcA.server);
> > > + g_clear_object(&test->srcB.server);
> > > + g_clear_object(&test->dstA.server);
> > > + g_clear_object(&test->dstB.server);
> > > + g_mutex_unlock(&mutex);
> > > +
> > > + return NULL;
> > > +}
> > > +
> > > +static gboolean
> > > +wait_for_migration_complete(gpointer user_data)
> > > +{
> > > + Test *test = user_data;
> > > + QDict *rsp_return;
> > > + bool stop = false;
> > > + const char *status;
> > > +
> > > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > > + status = qdict_get_str(rsp_return, "status");
> > > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > > + stop = true;
> > > + g_assert_cmpstr(status, ==,
> > > + test->migrate_fail ? "failed" : "completed");
> > > + }
> > > + qobject_unref(rsp_return);
> > > +
> > > + if (stop) {
> > > + g_main_loop_quit(test->loop);
> > > + }
> > > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > > +}
> > > +
> > > +static void migrate(QTestState *who, const char *uri)
> > > +{
> > > + QDict *args, *rsp;
> > > +
> > > + args = qdict_new();
> > > + qdict_put_str(args, "uri", uri);
> > > +
> > > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > > +
> > > + g_assert(qdict_haskey(rsp, "return"));
> > > + qobject_unref(rsp);
> > > +}
> > > +
> > > +static void
> > > +test_dbus_vmstate(Test *test)
> > > +{
> > > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > > +
> > > + g_mutex_lock(&mutex);
> > > + while (!test->dbus_loop) {
> > > + g_cond_wait(&cond, &mutex);
> > > + }
> > > +
> > > + src_qemu_args =
> > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > + "-object dbus-vmstate,id=dvB,addr=%s",
> > > + g_dbus_server_get_client_address(test->srcA.server),
> > > + g_dbus_server_get_client_address(test->srcB.server));
> > > +
> > > +
> > > + dst_qemu_args =
> > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > + "-object dbus-vmstate,id=dvB,addr=%s "
> > > + "-incoming %s",
> > > + g_dbus_server_get_client_address(test->dstA.server),
> > > + g_dbus_server_get_client_address(test->dstB.server),
> > > + uri);
> > > +
> > > + src_qemu = qtest_init(src_qemu_args);
> > > + dst_qemu = qtest_init(dst_qemu_args);
> > > +
> > > + test->loop = g_main_loop_new(NULL, TRUE);
> > > +
> > > + migrate(src_qemu, uri);
> > > + test->src_qemu = src_qemu;
> > > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > > +
> > > + g_main_loop_run(test->loop);
> > > + g_main_loop_unref(test->loop);
> > > +
> > > + g_free(uri);
> > > + qtest_quit(dst_qemu);
> > > + qtest_quit(src_qemu);
> > > + g_free(dst_qemu_args);
> > > + g_free(src_qemu_args);
> > > +
> > > + g_main_loop_quit(test->dbus_loop);
> > > + g_mutex_unlock(&mutex);
> > > +
> > > + g_thread_join(t);
> > > +}
> > > +
> > > +static void
> > > +check_migrated(TestServer *s, TestServer *d)
> > > +{
> > > + assert(s->save_called);
> > > + assert(!s->load_called);
> > > + assert(!d->save_called);
> > > + assert(d->load_called);
> > > +}
> > > +
> > > +static void
> > > +test_dbus_vmstate_migrate(void)
> > > +{
> > > + Test test = { };
> > > +
> > > + test_dbus_vmstate(&test);
> > > +
> > > + check_migrated(&test.srcA, &test.dstA);
> > > + check_migrated(&test.srcB, &test.dstB);
> > > +}
> > > +
> > > +int
> > > +main(int argc, char **argv)
> > > +{
> > > + GError *err = NULL;
> > > + int ret;
> > > +
> > > + g_test_init(&argc, &argv, NULL);
> > > +
> > > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > > + if (!workdir) {
> > > + g_error("Unable to create temporary dir: %s\n", err->message);
> > > + }
> > > +
> > > + qtest_add_func("/dbus-vmstate/migrate",
> > > + test_dbus_vmstate_migrate);
> > > +
> > > + ret = g_test_run();
> > > +
> > > + rmdir(workdir);
> > > + g_free(workdir);
> > > +
> > > + return ret;
> > > +}
> > > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > > new file mode 100644
> > > index 0000000000..cc8563be4c
> > > --- /dev/null
> > > +++ b/tests/dbus-vmstate1.xml
> > > @@ -0,0 +1,12 @@
> > > +<?xml version="1.0"?>
> > > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > > + <interface name="org.qemu.VMState1">
> > > + <property name="Id" type="s" access="read"/>
> > > + <method name="Load">
> > > + <arg type="ay" name="data" direction="in"/>
> > > + </method>
> > > + <method name="Save">
> > > + <arg type="ay" name="data" direction="out"/>
> > > + </method>
> > > + </interface>
> > > +</node>
> > > --
> > > 2.23.0.rc1
> > >
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Hi
On Thu, Aug 22, 2019 at 3:41 PM Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
>
> * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > Hi
> >
> > On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
> > <dgilbert@redhat.com> wrote:
> > >
> > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > When instanciated, this object will connect to the given D-Bus
> > > > bus. During migration, it will take the data from org.qemu.VMState1
> > > > instances.
> > > >
> > > > See documentation for further details.
> > >
> > > I'll leave the main review to someone who understands the details of
> > > DBUS, however from the migration side:
> > >
> > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > >
> > > <snip>
> > >
> > > > +
> > > > +static int
> > > > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > + uint8_t *data = NULL;
> > > > + int ret = -1;
> > > > + char id[256];
> > > > + unsigned int size;
> > >
> > > Higher level question; do you actually need a separate ID, or does
> > > the ID that's stored by the migration code in the section name
> > > give you enough uniqueness?
> >
> >
> > The ID stored in migration section name is based on the handler ID:
> > TYPE_DBUS_VMSTATE "-" handler_id
> >
> > By design, handler_id must be unique (and documented as such).
> >
> > Do you see a problem with that approach?
>
> OK, so if that's unique, why do you need an 'id' stored here?
Oh I see, that's mostly a relic of v1, where multiple ID
"sub-sections" would exist for each helper.
However, if we want to allow having several "sub-sections" again, that
might come handy to keep compatibility. It may be better to have a
simple version field for that instead.
>
> > >
> > > > + if (qemu_get_counted_string(f, id) == 0) {
> > > > + error_report("Invalid vmstate Id");
> > > > + goto end;
> > >
> > > I generally prefer to include something telling me where the error has
> > > come from, just to make it easier to track down if I see the error in
> > > a log; e.g. use __func__
> >
> > ok
> >
> > >
> > > > + }
> > > > +
> > > > + if (g_strcmp0(id, self->id)) {
> > > > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + size = qemu_get_be32(f);
> > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > + error_report("Invalid vmstate size: %u", size);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + data = g_malloc(size);
> > > > + if (qemu_get_buffer(f, data, size) != size) {
> > > > + error_report("Failed to read %u bytes", size);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > > > + error_report("Failed to restore Id '%s'", id);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + ret = 0;
> > > > +
> > > > +end:
> > > > + g_clear_pointer(&data, g_free);
> > > > + return ret;
> > > > +}
> > > > +
> > > > +static void
> > > > +dbus_save_state(QEMUFile *f, void *opaque)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > + GVariant *result = NULL, *child = NULL;
> > > > + const uint8_t *data;
> > > > + size_t size;
> > > > + GError *err = NULL;
> > > > +
> > > > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > > > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > > > + -1, NULL, &err);
> > > > + if (!result) {
> > > > + error_report("Failed to Save: %s", err->message);
> > > > + g_clear_error(&err);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + child = g_variant_get_child_value(result, 0);
> > > > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > > > + if (!data) {
> > > > + error_report("Failed to Save: not a byte array");
> > > > + goto end;
> > > > + }
> > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > + error_report("Too much vmstate data to save: %zu", size);
> > > > + goto end;
> > > > + }
> > > > +
> > > > + qemu_put_counted_string(f, self->id);
> > > > + qemu_put_be32(f, size);
> > > > + qemu_put_buffer(f, data, size);
> > > > +
> > > > +end:
> > > > + g_clear_pointer(&child, g_variant_unref);
> > > > + g_clear_pointer(&result, g_variant_unref);
> > > > +}
> > > > +
> > > > +static const SaveVMHandlers savevm_handlers = {
> > > > + .save_state = dbus_save_state,
> > > > + .load_state = dbus_load_state,
> > > > +};
> > > > +
> > > > +static void
> > > > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(uc);
> > > > + GError *err = NULL;
> > > > + GDBusConnection *bus = NULL;
> > > > + GDBusProxy *proxy = NULL;
> > > > + char *idstr = NULL;
> > > > +
> > > > + if (!self->dbus_addr) {
> > > > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > > > + return;
> > > > + }
> > > > +
> > > > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > > > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > > > + NULL, NULL, &err);
> > > > + if (err) {
> > > > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > > > + g_clear_error(&err);
> > > > + return;
> > > > + }
> > > > +
> > > > + self->bus = bus;
> > > > +
> > > > + proxy = g_dbus_proxy_new_sync(bus,
> > > > + G_DBUS_PROXY_FLAGS_NONE,
> > > > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > > > + NULL,
> > > > + "/org/qemu/VMState1",
> > > > + "org.qemu.VMState1",
> > > > + NULL, &err);
> > > > +
> > > > + if (err) {
> > > > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > > > + g_clear_error(&err);
> > > > + return;
> > > > + }
> > > > +
> > > > + self->proxy = proxy;
> > > > +
> > > > + self->id = dbus_proxy_get_id(proxy, &err);
> > > > + if (!self->id) {
> > > > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > > > + g_clear_error(&err);
> > > > + return;
> > > > + }
> > > > +
> > > > + idstr = get_idstr(self);
> > > > + if (register_savevm_live(NULL, idstr, 0, 0,
> > > > + &savevm_handlers, self) < 0) {
> > > > + error_setg(errp, "Failed to register savevm handler");
> > > > + }
> > >
> > > Can you try and avoid register_savevm_live if possible and just wire a
> > > vmsd onto the class like most other devices? We don't have many
> > > register_savevm_live calls, and I'd like to get them down to just the
> > > iterative devices.
> >
> > Sure if I could, but it's not a device.
> >
> > Perhaps we could have a qom interface for vmsd users? I can try that eventually.
>
> Hmm, why isn't it a device?
It doesn't need anything from Device (which is heavyweight), it is a
simple user-creatable object that holds a dbus connection and reacts
on migration events.
If you take slirp helper process as an example, it's a "service" for a
VM. Not a device. You could have the same helper for various devices
etc, or more helpers for the same device.
>
>
> Dave
>
> > thanks
> >
> > > Dave
> > >
> > >
> > > > + g_free(idstr);
> > > > +}
> > > > +
> > > > +static void
> > > > +dbus_vmstate_finalize(Object *o)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > + char *idstr = get_idstr(self);
> > > > +
> > > > + unregister_savevm(NULL, idstr, self);
> > > > +
> > > > + g_clear_object(&self->bus);
> > > > + g_clear_object(&self->proxy);
> > > > + g_free(self->dbus_addr);
> > > > + g_free(self->id);
> > > > + g_free(idstr);
> > > > +}
> > > > +
> > > > +static char *
> > > > +get_dbus_addr(Object *o, Error **errp)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > +
> > > > + return g_strdup(self->dbus_addr);
> > > > +}
> > > > +
> > > > +static void
> > > > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > > > +{
> > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > +
> > > > + g_free(self->dbus_addr);
> > > > + self->dbus_addr = g_strdup(str);
> > > > +}
> > > > +
> > > > +static void
> > > > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > > > +{
> > > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > > > +
> > > > + ucc->complete = dbus_vmstate_complete;
> > > > +
> > > > + object_class_property_add_str(oc, "addr",
> > > > + get_dbus_addr, set_dbus_addr,
> > > > + &error_abort);
> > > > +}
> > > > +
> > > > +static const TypeInfo dbus_vmstate_info = {
> > > > + .name = TYPE_DBUS_VMSTATE,
> > > > + .parent = TYPE_OBJECT,
> > > > + .instance_size = sizeof(DBusVMState),
> > > > + .instance_finalize = dbus_vmstate_finalize,
> > > > + .class_size = sizeof(DBusVMStateClass),
> > > > + .class_init = dbus_vmstate_class_init,
> > > > + .interfaces = (InterfaceInfo[]) {
> > > > + { TYPE_USER_CREATABLE },
> > > > + { }
> > > > + }
> > > > +};
> > > > +
> > > > +static void
> > > > +register_types(void)
> > > > +{
> > > > + type_register_static(&dbus_vmstate_info);
> > > > +}
> > > > +
> > > > +type_init(register_types);
> > > > diff --git a/configure b/configure
> > > > index 714e7fb6a1..e5b34f5ca7 100755
> > > > --- a/configure
> > > > +++ b/configure
> > > > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > > > gio=yes
> > > > gio_cflags=$($pkg_config --cflags gio-2.0)
> > > > gio_libs=$($pkg_config --libs gio-2.0)
> > > > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > > > else
> > > > gio=no
> > > > fi
> > > >
> > > > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > > > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > > > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > > > +fi
> > > > +
> > > > # Sanity check that the current size_t matches the
> > > > # size that glib thinks it should be. This catches
> > > > # problems on multi-arch where people try to build
> > > > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > > > echo "CONFIG_GIO=y" >> $config_host_mak
> > > > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > > > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > > > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > > > fi
> > > > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > > > if test "$gnutls" = "yes" ; then
> > > > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > > > new file mode 100644
> > > > index 0000000000..4a32a183fb
> > > > --- /dev/null
> > > > +++ b/docs/interop/dbus-vmstate.rst
> > > > @@ -0,0 +1,63 @@
> > > > +============
> > > > +DBus VMState
> > > > +============
> > > > +
> > > > +Introduction
> > > > +============
> > > > +
> > > > +Helper processes may have their state migrated with the help of
> > > > +QEMU "dbus-vmstate" objects.
> > > > +
> > > > +At this point, the connection to the helper is done in DBus
> > > > +peer-to-peer mode (no initial Hello, and no bus name for
> > > > +communication). The helper must be listening to the given address.
> > > > +
> > > > +Helper may save arbitrary data to be transferred in the migration
> > > > +stream and restored/loaded on destination.
> > > > +
> > > > +The data amount to be transferred is limited to 1Mb. The state must be
> > > > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > > > +reply anyway, and migration would fail if the data isn't given quickly
> > > > +enough)
> > > > +
> > > > +Interface
> > > > +=========
> > > > +
> > > > +On /org/qemu/VMState1 object path:
> > > > +
> > > > +.. code:: xml
> > > > +
> > > > + <interface name="org.qemu.VMState1">
> > > > + <property name="Id" type="s" access="read"/>
> > > > + <method name="Load">
> > > > + <arg type="ay" name="data" direction="in"/>
> > > > + </method>
> > > > + <method name="Save">
> > > > + <arg type="ay" name="data" direction="out"/>
> > > > + </method>
> > > > + </interface>
> > > > +
> > > > +"Id" property
> > > > +-------------
> > > > +
> > > > +A utf8 encoded string that identifies the helper uniquely.
> > > > +Must be <256 bytes.
> > > > +
> > > > +Load(in u8[] bytes) method
> > > > +--------------------------
> > > > +
> > > > +The method called on destination with the state to restore.
> > > > +
> > > > +The helper may be initially started in a waiting state (with
> > > > +an --incoming argument for example), and it may resume on load
> > > > +success.
> > > > +
> > > > +An error may be returned to the caller.
> > > > +
> > > > +Save(out u8[] bytes) method
> > > > +---------------------------
> > > > +
> > > > +The method called on the source to get the current state to be
> > > > +migrated. The helper should continue to run normally.
> > > > +
> > > > +An error may be returned to the caller.
> > > > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > > > index b4bfcab417..6bb173cfa6 100644
> > > > --- a/docs/interop/index.rst
> > > > +++ b/docs/interop/index.rst
> > > > @@ -13,6 +13,7 @@ Contents:
> > > > :maxdepth: 2
> > > >
> > > > bitmaps
> > > > + dbus-vmstate
> > > > live-block-operations
> > > > pr-helper
> > > > vhost-user
> > > > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > > > index fd7fdb8658..2c610086a7 100644
> > > > --- a/tests/Makefile.include
> > > > +++ b/tests/Makefile.include
> > > > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > > > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > > > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > > > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > > > -
> > > > +ifneq ($(GDBUS_CODEGEN),)
> > > > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > > > +endif
> > > > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > > > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > > > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > > > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > > > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > > > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> > > >
> > > > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > > > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > > > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > > > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > > > + "GEN","$(@:%-timestamp=%)")
> > > > + @>$@
> > > > +
> > > > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > > > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > > > +
> > > > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > > > +
> > > > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > > > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > > > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > > > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > > > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > > > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > > > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > > > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > > > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > > > @@ -1172,6 +1187,7 @@ check-clean:
> > > > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > > > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > > > rm -f tests/test-qapi-gen-timestamp
> > > > + rm -f tests/dbus-vmstate1-gen-timestamp
> > > > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> > > >
> > > > clean: check-clean
> > > > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > > > new file mode 100644
> > > > index 0000000000..45d44916d2
> > > > --- /dev/null
> > > > +++ b/tests/dbus-vmstate-test.c
> > > > @@ -0,0 +1,371 @@
> > > > +#include "qemu/osdep.h"
> > > > +#include <glib/gstdio.h>
> > > > +#include <gio/gio.h>
> > > > +#include "libqtest.h"
> > > > +#include "qemu-common.h"
> > > > +#include "dbus-vmstate1.h"
> > > > +
> > > > +static char *workdir;
> > > > +
> > > > +typedef struct TestServerId {
> > > > + const char *name;
> > > > + const char *data;
> > > > + size_t size;
> > > > +} TestServerId;
> > > > +
> > > > +static const TestServerId idA = {
> > > > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > > > +};
> > > > +
> > > > +static const TestServerId idB = {
> > > > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > > > +};
> > > > +
> > > > +typedef struct TestServer {
> > > > + const TestServerId *id;
> > > > + bool save_called;
> > > > + bool load_called;
> > > > + GDBusObjectManagerServer *om;
> > > > + GDBusServer *server;
> > > > +} TestServer;
> > > > +
> > > > +typedef struct Test {
> > > > + bool migrate_fail;
> > > > + TestServer srcA;
> > > > + TestServer dstA;
> > > > + TestServer srcB;
> > > > + TestServer dstB;
> > > > + GMainLoop *loop, *dbus_loop;
> > > > + QTestState *src_qemu;
> > > > +} Test;
> > > > +
> > > > +GMutex mutex;
> > > > +GCond cond;
> > > > +
> > > > +static gboolean
> > > > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > + const gchar *arg_data, gpointer user_data)
> > > > +{
> > > > + TestServer *h = user_data;
> > > > + GVariant *args, *var;
> > > > + const uint8_t *data;
> > > > + size_t size;
> > > > +
> > > > + args = g_dbus_method_invocation_get_parameters(invocation);
> > > > + var = g_variant_get_child_value(args, 0);
> > > > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > > > + g_assert_cmpuint(size, ==, h->id->size);
> > > > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > > > + h->load_called = true;
> > > > + g_variant_unref(var);
> > > > +
> > > > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > > > + return TRUE;
> > > > +}
> > > > +
> > > > +static gboolean
> > > > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > + gpointer user_data)
> > > > +{
> > > > + TestServer *h = user_data;
> > > > + GVariant *var;
> > > > +
> > > > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > > > + h->id->data, h->id->size, sizeof(char));
> > > > + g_dbus_method_invocation_return_value(invocation,
> > > > + g_variant_new("(@ay)", var));
> > > > + h->save_called = true;
> > > > +
> > > > + return TRUE;
> > > > +}
> > > > +
> > > > +static void
> > > > +connection_closed(GDBusConnection *connection,
> > > > + gboolean remote_peer_vanished,
> > > > + GError *Error,
> > > > + gpointer user_data)
> > > > +{
> > > > + TestServer *h = user_data;
> > > > +
> > > > + g_clear_object(&h->om);
> > > > + g_clear_object(&connection);
> > > > +}
> > > > +
> > > > +static GDBusObjectManagerServer *
> > > > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > > > +{
> > > > + TestServer *h = user_data;
> > > > + GDBusObjectManagerServer *om;
> > > > + GDBusObjectSkeleton *sk;
> > > > + VMState1 *v;
> > > > +
> > > > + om = g_dbus_object_manager_server_new("/org/qemu");
> > > > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > > > +
> > > > + v = vmstate1_skeleton_new();
> > > > + g_object_set(v, "id", h->id->name, NULL);
> > > > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > > > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > > > +
> > > > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > > > + g_dbus_object_manager_server_export(om, sk);
> > > > + g_dbus_object_manager_server_set_connection(om, conn);
> > > > +
> > > > + g_clear_object(&v);
> > > > + g_clear_object(&sk);
> > > > +
> > > > + return om;
> > > > +}
> > > > +
> > > > +static gboolean
> > > > +on_new_connection(GDBusServer *server,
> > > > + GDBusConnection *connection,
> > > > + gpointer user_data)
> > > > +{
> > > > + TestServer *h = user_data;
> > > > +
> > > > + g_object_ref(connection);
> > > > + g_signal_connect(connection, "closed",
> > > > + G_CALLBACK(connection_closed), user_data);
> > > > + h->om = get_omserver(connection, user_data);
> > > > +
> > > > + return TRUE;
> > > > +}
> > > > +
> > > > +static gboolean
> > > > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > > > + const gchar *mechanism,
> > > > + gpointer user_data)
> > > > +{
> > > > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > > > +}
> > > > +
> > > > +static gboolean
> > > > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > > > + GIOStream *stream,
> > > > + GCredentials *credentials,
> > > > + gpointer user_data)
> > > > +{
> > > > + gboolean authorized = FALSE;
> > > > +
> > > > + if (credentials != NULL) {
> > > > + GCredentials *own_credentials = g_credentials_new();
> > > > +
> > > > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > > > + authorized = TRUE;
> > > > + }
> > > > +
> > > > + g_clear_object(&own_credentials);
> > > > + }
> > > > +
> > > > + return authorized;
> > > > +}
> > > > +
> > > > +static GDBusServer *
> > > > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > > > +{
> > > > + GDBusAuthObserver *observer = NULL;
> > > > + GDBusServer *server = NULL;
> > > > + gchar *guid = NULL;
> > > > + GError *error = NULL;
> > > > + char *addr = NULL;
> > > > +
> > > > + h->id = id;
> > > > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > > > + guid = g_dbus_generate_guid();
> > > > + observer = g_dbus_auth_observer_new();
> > > > + g_signal_connect(observer, "allow-mechanism",
> > > > + G_CALLBACK(allow_mechanism_cb), h);
> > > > + g_signal_connect(observer, "authorize-authenticated-peer",
> > > > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > > > +
> > > > + server = g_dbus_server_new_sync(addr,
> > > > + G_DBUS_SERVER_FLAGS_NONE,
> > > > + guid,
> > > > + observer,
> > > > + NULL, /* GCancellable */
> > > > + &error);
> > > > + g_dbus_server_start(server);
> > > > + g_clear_object(&observer);
> > > > + g_free(guid);
> > > > +
> > > > + if (server == NULL) {
> > > > + g_printerr("Error creating server at address %s: %s\n",
> > > > + addr, error->message);
> > > > + g_error_free(error);
> > > > + return NULL;
> > > > + }
> > > > +
> > > > + g_signal_connect(server, "new-connection",
> > > > + G_CALLBACK(on_new_connection), h);
> > > > +
> > > > + g_free(addr);
> > > > + return server;
> > > > +}
> > > > +
> > > > +
> > > > +static gpointer
> > > > +dbus_thread(gpointer p)
> > > > +{
> > > > + Test *test = p;
> > > > + GMainContext *context = g_main_context_new();
> > > > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > > > +
> > > > + g_main_context_push_thread_default(context);
> > > > +
> > > > + g_mutex_lock(&mutex);
> > > > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > > > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > > > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > > > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > > > + test->dbus_loop = loop;
> > > > + g_cond_signal(&cond);
> > > > + g_mutex_unlock(&mutex);
> > > > +
> > > > + g_main_loop_run(loop);
> > > > +
> > > > + g_main_loop_unref(loop);
> > > > + g_main_context_unref(context);
> > > > +
> > > > + g_mutex_lock(&mutex);
> > > > + g_clear_object(&test->srcA.server);
> > > > + g_clear_object(&test->srcB.server);
> > > > + g_clear_object(&test->dstA.server);
> > > > + g_clear_object(&test->dstB.server);
> > > > + g_mutex_unlock(&mutex);
> > > > +
> > > > + return NULL;
> > > > +}
> > > > +
> > > > +static gboolean
> > > > +wait_for_migration_complete(gpointer user_data)
> > > > +{
> > > > + Test *test = user_data;
> > > > + QDict *rsp_return;
> > > > + bool stop = false;
> > > > + const char *status;
> > > > +
> > > > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > > > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > > > + status = qdict_get_str(rsp_return, "status");
> > > > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > > > + stop = true;
> > > > + g_assert_cmpstr(status, ==,
> > > > + test->migrate_fail ? "failed" : "completed");
> > > > + }
> > > > + qobject_unref(rsp_return);
> > > > +
> > > > + if (stop) {
> > > > + g_main_loop_quit(test->loop);
> > > > + }
> > > > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > > > +}
> > > > +
> > > > +static void migrate(QTestState *who, const char *uri)
> > > > +{
> > > > + QDict *args, *rsp;
> > > > +
> > > > + args = qdict_new();
> > > > + qdict_put_str(args, "uri", uri);
> > > > +
> > > > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > > > +
> > > > + g_assert(qdict_haskey(rsp, "return"));
> > > > + qobject_unref(rsp);
> > > > +}
> > > > +
> > > > +static void
> > > > +test_dbus_vmstate(Test *test)
> > > > +{
> > > > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > > > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > > > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > > > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > > > +
> > > > + g_mutex_lock(&mutex);
> > > > + while (!test->dbus_loop) {
> > > > + g_cond_wait(&cond, &mutex);
> > > > + }
> > > > +
> > > > + src_qemu_args =
> > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > + "-object dbus-vmstate,id=dvB,addr=%s",
> > > > + g_dbus_server_get_client_address(test->srcA.server),
> > > > + g_dbus_server_get_client_address(test->srcB.server));
> > > > +
> > > > +
> > > > + dst_qemu_args =
> > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > + "-object dbus-vmstate,id=dvB,addr=%s "
> > > > + "-incoming %s",
> > > > + g_dbus_server_get_client_address(test->dstA.server),
> > > > + g_dbus_server_get_client_address(test->dstB.server),
> > > > + uri);
> > > > +
> > > > + src_qemu = qtest_init(src_qemu_args);
> > > > + dst_qemu = qtest_init(dst_qemu_args);
> > > > +
> > > > + test->loop = g_main_loop_new(NULL, TRUE);
> > > > +
> > > > + migrate(src_qemu, uri);
> > > > + test->src_qemu = src_qemu;
> > > > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > > > +
> > > > + g_main_loop_run(test->loop);
> > > > + g_main_loop_unref(test->loop);
> > > > +
> > > > + g_free(uri);
> > > > + qtest_quit(dst_qemu);
> > > > + qtest_quit(src_qemu);
> > > > + g_free(dst_qemu_args);
> > > > + g_free(src_qemu_args);
> > > > +
> > > > + g_main_loop_quit(test->dbus_loop);
> > > > + g_mutex_unlock(&mutex);
> > > > +
> > > > + g_thread_join(t);
> > > > +}
> > > > +
> > > > +static void
> > > > +check_migrated(TestServer *s, TestServer *d)
> > > > +{
> > > > + assert(s->save_called);
> > > > + assert(!s->load_called);
> > > > + assert(!d->save_called);
> > > > + assert(d->load_called);
> > > > +}
> > > > +
> > > > +static void
> > > > +test_dbus_vmstate_migrate(void)
> > > > +{
> > > > + Test test = { };
> > > > +
> > > > + test_dbus_vmstate(&test);
> > > > +
> > > > + check_migrated(&test.srcA, &test.dstA);
> > > > + check_migrated(&test.srcB, &test.dstB);
> > > > +}
> > > > +
> > > > +int
> > > > +main(int argc, char **argv)
> > > > +{
> > > > + GError *err = NULL;
> > > > + int ret;
> > > > +
> > > > + g_test_init(&argc, &argv, NULL);
> > > > +
> > > > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > > > + if (!workdir) {
> > > > + g_error("Unable to create temporary dir: %s\n", err->message);
> > > > + }
> > > > +
> > > > + qtest_add_func("/dbus-vmstate/migrate",
> > > > + test_dbus_vmstate_migrate);
> > > > +
> > > > + ret = g_test_run();
> > > > +
> > > > + rmdir(workdir);
> > > > + g_free(workdir);
> > > > +
> > > > + return ret;
> > > > +}
> > > > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > > > new file mode 100644
> > > > index 0000000000..cc8563be4c
> > > > --- /dev/null
> > > > +++ b/tests/dbus-vmstate1.xml
> > > > @@ -0,0 +1,12 @@
> > > > +<?xml version="1.0"?>
> > > > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > > > + <interface name="org.qemu.VMState1">
> > > > + <property name="Id" type="s" access="read"/>
> > > > + <method name="Load">
> > > > + <arg type="ay" name="data" direction="in"/>
> > > > + </method>
> > > > + <method name="Save">
> > > > + <arg type="ay" name="data" direction="out"/>
> > > > + </method>
> > > > + </interface>
> > > > +</node>
> > > > --
> > > > 2.23.0.rc1
> > > >
> > > --
> > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> Hi
>
> On Thu, Aug 22, 2019 at 3:41 PM Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> >
> > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > Hi
> > >
> > > On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
> > > <dgilbert@redhat.com> wrote:
> > > >
> > > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > > When instanciated, this object will connect to the given D-Bus
> > > > > bus. During migration, it will take the data from org.qemu.VMState1
> > > > > instances.
> > > > >
> > > > > See documentation for further details.
> > > >
> > > > I'll leave the main review to someone who understands the details of
> > > > DBUS, however from the migration side:
> > > >
> > > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > > >
> > > > <snip>
> > > >
> > > > > +
> > > > > +static int
> > > > > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > + uint8_t *data = NULL;
> > > > > + int ret = -1;
> > > > > + char id[256];
> > > > > + unsigned int size;
> > > >
> > > > Higher level question; do you actually need a separate ID, or does
> > > > the ID that's stored by the migration code in the section name
> > > > give you enough uniqueness?
> > >
> > >
> > > The ID stored in migration section name is based on the handler ID:
> > > TYPE_DBUS_VMSTATE "-" handler_id
> > >
> > > By design, handler_id must be unique (and documented as such).
> > >
> > > Do you see a problem with that approach?
> >
> > OK, so if that's unique, why do you need an 'id' stored here?
>
> Oh I see, that's mostly a relic of v1, where multiple ID
> "sub-sections" would exist for each helper.
>
> However, if we want to allow having several "sub-sections" again, that
> might come handy to keep compatibility. It may be better to have a
> simple version field for that instead.
OK, that's fine
> >
> > > >
> > > > > + if (qemu_get_counted_string(f, id) == 0) {
> > > > > + error_report("Invalid vmstate Id");
> > > > > + goto end;
> > > >
> > > > I generally prefer to include something telling me where the error has
> > > > come from, just to make it easier to track down if I see the error in
> > > > a log; e.g. use __func__
> > >
> > > ok
> > >
> > > >
> > > > > + }
> > > > > +
> > > > > + if (g_strcmp0(id, self->id)) {
> > > > > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + size = qemu_get_be32(f);
> > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > + error_report("Invalid vmstate size: %u", size);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + data = g_malloc(size);
> > > > > + if (qemu_get_buffer(f, data, size) != size) {
> > > > > + error_report("Failed to read %u bytes", size);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > > > > + error_report("Failed to restore Id '%s'", id);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + ret = 0;
> > > > > +
> > > > > +end:
> > > > > + g_clear_pointer(&data, g_free);
> > > > > + return ret;
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +dbus_save_state(QEMUFile *f, void *opaque)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > + GVariant *result = NULL, *child = NULL;
> > > > > + const uint8_t *data;
> > > > > + size_t size;
> > > > > + GError *err = NULL;
> > > > > +
> > > > > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > > > > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > > > > + -1, NULL, &err);
> > > > > + if (!result) {
> > > > > + error_report("Failed to Save: %s", err->message);
> > > > > + g_clear_error(&err);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + child = g_variant_get_child_value(result, 0);
> > > > > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > > > > + if (!data) {
> > > > > + error_report("Failed to Save: not a byte array");
> > > > > + goto end;
> > > > > + }
> > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > + error_report("Too much vmstate data to save: %zu", size);
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + qemu_put_counted_string(f, self->id);
> > > > > + qemu_put_be32(f, size);
> > > > > + qemu_put_buffer(f, data, size);
> > > > > +
> > > > > +end:
> > > > > + g_clear_pointer(&child, g_variant_unref);
> > > > > + g_clear_pointer(&result, g_variant_unref);
> > > > > +}
> > > > > +
> > > > > +static const SaveVMHandlers savevm_handlers = {
> > > > > + .save_state = dbus_save_state,
> > > > > + .load_state = dbus_load_state,
> > > > > +};
> > > > > +
> > > > > +static void
> > > > > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(uc);
> > > > > + GError *err = NULL;
> > > > > + GDBusConnection *bus = NULL;
> > > > > + GDBusProxy *proxy = NULL;
> > > > > + char *idstr = NULL;
> > > > > +
> > > > > + if (!self->dbus_addr) {
> > > > > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > > > > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > > > > + NULL, NULL, &err);
> > > > > + if (err) {
> > > > > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > > > > + g_clear_error(&err);
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + self->bus = bus;
> > > > > +
> > > > > + proxy = g_dbus_proxy_new_sync(bus,
> > > > > + G_DBUS_PROXY_FLAGS_NONE,
> > > > > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > > > > + NULL,
> > > > > + "/org/qemu/VMState1",
> > > > > + "org.qemu.VMState1",
> > > > > + NULL, &err);
> > > > > +
> > > > > + if (err) {
> > > > > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > > > > + g_clear_error(&err);
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + self->proxy = proxy;
> > > > > +
> > > > > + self->id = dbus_proxy_get_id(proxy, &err);
> > > > > + if (!self->id) {
> > > > > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > > > > + g_clear_error(&err);
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + idstr = get_idstr(self);
> > > > > + if (register_savevm_live(NULL, idstr, 0, 0,
> > > > > + &savevm_handlers, self) < 0) {
> > > > > + error_setg(errp, "Failed to register savevm handler");
> > > > > + }
> > > >
> > > > Can you try and avoid register_savevm_live if possible and just wire a
> > > > vmsd onto the class like most other devices? We don't have many
> > > > register_savevm_live calls, and I'd like to get them down to just the
> > > > iterative devices.
> > >
> > > Sure if I could, but it's not a device.
> > >
> > > Perhaps we could have a qom interface for vmsd users? I can try that eventually.
> >
> > Hmm, why isn't it a device?
>
> It doesn't need anything from Device (which is heavyweight), it is a
> simple user-creatable object that holds a dbus connection and reacts
> on migration events.
>
> If you take slirp helper process as an example, it's a "service" for a
> VM. Not a device. You could have the same helper for various devices
> etc, or more helpers for the same device.
I think you're better calling this a device; the slirp world doesn't fit
nicely either and it would be better if it was a device as well.
Dave
> >
> >
> > Dave
> >
> > > thanks
> > >
> > > > Dave
> > > >
> > > >
> > > > > + g_free(idstr);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +dbus_vmstate_finalize(Object *o)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > + char *idstr = get_idstr(self);
> > > > > +
> > > > > + unregister_savevm(NULL, idstr, self);
> > > > > +
> > > > > + g_clear_object(&self->bus);
> > > > > + g_clear_object(&self->proxy);
> > > > > + g_free(self->dbus_addr);
> > > > > + g_free(self->id);
> > > > > + g_free(idstr);
> > > > > +}
> > > > > +
> > > > > +static char *
> > > > > +get_dbus_addr(Object *o, Error **errp)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > +
> > > > > + return g_strdup(self->dbus_addr);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > > > > +{
> > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > +
> > > > > + g_free(self->dbus_addr);
> > > > > + self->dbus_addr = g_strdup(str);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > > > > +{
> > > > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > > > > +
> > > > > + ucc->complete = dbus_vmstate_complete;
> > > > > +
> > > > > + object_class_property_add_str(oc, "addr",
> > > > > + get_dbus_addr, set_dbus_addr,
> > > > > + &error_abort);
> > > > > +}
> > > > > +
> > > > > +static const TypeInfo dbus_vmstate_info = {
> > > > > + .name = TYPE_DBUS_VMSTATE,
> > > > > + .parent = TYPE_OBJECT,
> > > > > + .instance_size = sizeof(DBusVMState),
> > > > > + .instance_finalize = dbus_vmstate_finalize,
> > > > > + .class_size = sizeof(DBusVMStateClass),
> > > > > + .class_init = dbus_vmstate_class_init,
> > > > > + .interfaces = (InterfaceInfo[]) {
> > > > > + { TYPE_USER_CREATABLE },
> > > > > + { }
> > > > > + }
> > > > > +};
> > > > > +
> > > > > +static void
> > > > > +register_types(void)
> > > > > +{
> > > > > + type_register_static(&dbus_vmstate_info);
> > > > > +}
> > > > > +
> > > > > +type_init(register_types);
> > > > > diff --git a/configure b/configure
> > > > > index 714e7fb6a1..e5b34f5ca7 100755
> > > > > --- a/configure
> > > > > +++ b/configure
> > > > > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > > > > gio=yes
> > > > > gio_cflags=$($pkg_config --cflags gio-2.0)
> > > > > gio_libs=$($pkg_config --libs gio-2.0)
> > > > > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > > > > else
> > > > > gio=no
> > > > > fi
> > > > >
> > > > > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > > > > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > > > > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > > > > +fi
> > > > > +
> > > > > # Sanity check that the current size_t matches the
> > > > > # size that glib thinks it should be. This catches
> > > > > # problems on multi-arch where people try to build
> > > > > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > > > > echo "CONFIG_GIO=y" >> $config_host_mak
> > > > > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > > > > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > > > > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > > > > fi
> > > > > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > > > > if test "$gnutls" = "yes" ; then
> > > > > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > > > > new file mode 100644
> > > > > index 0000000000..4a32a183fb
> > > > > --- /dev/null
> > > > > +++ b/docs/interop/dbus-vmstate.rst
> > > > > @@ -0,0 +1,63 @@
> > > > > +============
> > > > > +DBus VMState
> > > > > +============
> > > > > +
> > > > > +Introduction
> > > > > +============
> > > > > +
> > > > > +Helper processes may have their state migrated with the help of
> > > > > +QEMU "dbus-vmstate" objects.
> > > > > +
> > > > > +At this point, the connection to the helper is done in DBus
> > > > > +peer-to-peer mode (no initial Hello, and no bus name for
> > > > > +communication). The helper must be listening to the given address.
> > > > > +
> > > > > +Helper may save arbitrary data to be transferred in the migration
> > > > > +stream and restored/loaded on destination.
> > > > > +
> > > > > +The data amount to be transferred is limited to 1Mb. The state must be
> > > > > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > > > > +reply anyway, and migration would fail if the data isn't given quickly
> > > > > +enough)
> > > > > +
> > > > > +Interface
> > > > > +=========
> > > > > +
> > > > > +On /org/qemu/VMState1 object path:
> > > > > +
> > > > > +.. code:: xml
> > > > > +
> > > > > + <interface name="org.qemu.VMState1">
> > > > > + <property name="Id" type="s" access="read"/>
> > > > > + <method name="Load">
> > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > + </method>
> > > > > + <method name="Save">
> > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > + </method>
> > > > > + </interface>
> > > > > +
> > > > > +"Id" property
> > > > > +-------------
> > > > > +
> > > > > +A utf8 encoded string that identifies the helper uniquely.
> > > > > +Must be <256 bytes.
> > > > > +
> > > > > +Load(in u8[] bytes) method
> > > > > +--------------------------
> > > > > +
> > > > > +The method called on destination with the state to restore.
> > > > > +
> > > > > +The helper may be initially started in a waiting state (with
> > > > > +an --incoming argument for example), and it may resume on load
> > > > > +success.
> > > > > +
> > > > > +An error may be returned to the caller.
> > > > > +
> > > > > +Save(out u8[] bytes) method
> > > > > +---------------------------
> > > > > +
> > > > > +The method called on the source to get the current state to be
> > > > > +migrated. The helper should continue to run normally.
> > > > > +
> > > > > +An error may be returned to the caller.
> > > > > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > > > > index b4bfcab417..6bb173cfa6 100644
> > > > > --- a/docs/interop/index.rst
> > > > > +++ b/docs/interop/index.rst
> > > > > @@ -13,6 +13,7 @@ Contents:
> > > > > :maxdepth: 2
> > > > >
> > > > > bitmaps
> > > > > + dbus-vmstate
> > > > > live-block-operations
> > > > > pr-helper
> > > > > vhost-user
> > > > > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > > > > index fd7fdb8658..2c610086a7 100644
> > > > > --- a/tests/Makefile.include
> > > > > +++ b/tests/Makefile.include
> > > > > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > > > > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > > > > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > > > > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > > > > -
> > > > > +ifneq ($(GDBUS_CODEGEN),)
> > > > > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > > > > +endif
> > > > > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > > > > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > > > > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > > > > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > > > > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > > > > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> > > > >
> > > > > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > > > > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > > > > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > > > > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > > > > + "GEN","$(@:%-timestamp=%)")
> > > > > + @>$@
> > > > > +
> > > > > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > > > > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > > > > +
> > > > > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > > > > +
> > > > > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > > > > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > > > > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > > > > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > > > > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > > > > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > > > > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > > > > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > > > > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > > > > @@ -1172,6 +1187,7 @@ check-clean:
> > > > > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > > > > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > > > > rm -f tests/test-qapi-gen-timestamp
> > > > > + rm -f tests/dbus-vmstate1-gen-timestamp
> > > > > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> > > > >
> > > > > clean: check-clean
> > > > > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > > > > new file mode 100644
> > > > > index 0000000000..45d44916d2
> > > > > --- /dev/null
> > > > > +++ b/tests/dbus-vmstate-test.c
> > > > > @@ -0,0 +1,371 @@
> > > > > +#include "qemu/osdep.h"
> > > > > +#include <glib/gstdio.h>
> > > > > +#include <gio/gio.h>
> > > > > +#include "libqtest.h"
> > > > > +#include "qemu-common.h"
> > > > > +#include "dbus-vmstate1.h"
> > > > > +
> > > > > +static char *workdir;
> > > > > +
> > > > > +typedef struct TestServerId {
> > > > > + const char *name;
> > > > > + const char *data;
> > > > > + size_t size;
> > > > > +} TestServerId;
> > > > > +
> > > > > +static const TestServerId idA = {
> > > > > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > > > > +};
> > > > > +
> > > > > +static const TestServerId idB = {
> > > > > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > > > > +};
> > > > > +
> > > > > +typedef struct TestServer {
> > > > > + const TestServerId *id;
> > > > > + bool save_called;
> > > > > + bool load_called;
> > > > > + GDBusObjectManagerServer *om;
> > > > > + GDBusServer *server;
> > > > > +} TestServer;
> > > > > +
> > > > > +typedef struct Test {
> > > > > + bool migrate_fail;
> > > > > + TestServer srcA;
> > > > > + TestServer dstA;
> > > > > + TestServer srcB;
> > > > > + TestServer dstB;
> > > > > + GMainLoop *loop, *dbus_loop;
> > > > > + QTestState *src_qemu;
> > > > > +} Test;
> > > > > +
> > > > > +GMutex mutex;
> > > > > +GCond cond;
> > > > > +
> > > > > +static gboolean
> > > > > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > + const gchar *arg_data, gpointer user_data)
> > > > > +{
> > > > > + TestServer *h = user_data;
> > > > > + GVariant *args, *var;
> > > > > + const uint8_t *data;
> > > > > + size_t size;
> > > > > +
> > > > > + args = g_dbus_method_invocation_get_parameters(invocation);
> > > > > + var = g_variant_get_child_value(args, 0);
> > > > > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > > > > + g_assert_cmpuint(size, ==, h->id->size);
> > > > > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > > > > + h->load_called = true;
> > > > > + g_variant_unref(var);
> > > > > +
> > > > > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > > > > + return TRUE;
> > > > > +}
> > > > > +
> > > > > +static gboolean
> > > > > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > + gpointer user_data)
> > > > > +{
> > > > > + TestServer *h = user_data;
> > > > > + GVariant *var;
> > > > > +
> > > > > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > > > > + h->id->data, h->id->size, sizeof(char));
> > > > > + g_dbus_method_invocation_return_value(invocation,
> > > > > + g_variant_new("(@ay)", var));
> > > > > + h->save_called = true;
> > > > > +
> > > > > + return TRUE;
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +connection_closed(GDBusConnection *connection,
> > > > > + gboolean remote_peer_vanished,
> > > > > + GError *Error,
> > > > > + gpointer user_data)
> > > > > +{
> > > > > + TestServer *h = user_data;
> > > > > +
> > > > > + g_clear_object(&h->om);
> > > > > + g_clear_object(&connection);
> > > > > +}
> > > > > +
> > > > > +static GDBusObjectManagerServer *
> > > > > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > > > > +{
> > > > > + TestServer *h = user_data;
> > > > > + GDBusObjectManagerServer *om;
> > > > > + GDBusObjectSkeleton *sk;
> > > > > + VMState1 *v;
> > > > > +
> > > > > + om = g_dbus_object_manager_server_new("/org/qemu");
> > > > > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > > > > +
> > > > > + v = vmstate1_skeleton_new();
> > > > > + g_object_set(v, "id", h->id->name, NULL);
> > > > > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > > > > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > > > > +
> > > > > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > > > > + g_dbus_object_manager_server_export(om, sk);
> > > > > + g_dbus_object_manager_server_set_connection(om, conn);
> > > > > +
> > > > > + g_clear_object(&v);
> > > > > + g_clear_object(&sk);
> > > > > +
> > > > > + return om;
> > > > > +}
> > > > > +
> > > > > +static gboolean
> > > > > +on_new_connection(GDBusServer *server,
> > > > > + GDBusConnection *connection,
> > > > > + gpointer user_data)
> > > > > +{
> > > > > + TestServer *h = user_data;
> > > > > +
> > > > > + g_object_ref(connection);
> > > > > + g_signal_connect(connection, "closed",
> > > > > + G_CALLBACK(connection_closed), user_data);
> > > > > + h->om = get_omserver(connection, user_data);
> > > > > +
> > > > > + return TRUE;
> > > > > +}
> > > > > +
> > > > > +static gboolean
> > > > > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > > > > + const gchar *mechanism,
> > > > > + gpointer user_data)
> > > > > +{
> > > > > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > > > > +}
> > > > > +
> > > > > +static gboolean
> > > > > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > > > > + GIOStream *stream,
> > > > > + GCredentials *credentials,
> > > > > + gpointer user_data)
> > > > > +{
> > > > > + gboolean authorized = FALSE;
> > > > > +
> > > > > + if (credentials != NULL) {
> > > > > + GCredentials *own_credentials = g_credentials_new();
> > > > > +
> > > > > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > > > > + authorized = TRUE;
> > > > > + }
> > > > > +
> > > > > + g_clear_object(&own_credentials);
> > > > > + }
> > > > > +
> > > > > + return authorized;
> > > > > +}
> > > > > +
> > > > > +static GDBusServer *
> > > > > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > > > > +{
> > > > > + GDBusAuthObserver *observer = NULL;
> > > > > + GDBusServer *server = NULL;
> > > > > + gchar *guid = NULL;
> > > > > + GError *error = NULL;
> > > > > + char *addr = NULL;
> > > > > +
> > > > > + h->id = id;
> > > > > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > > > > + guid = g_dbus_generate_guid();
> > > > > + observer = g_dbus_auth_observer_new();
> > > > > + g_signal_connect(observer, "allow-mechanism",
> > > > > + G_CALLBACK(allow_mechanism_cb), h);
> > > > > + g_signal_connect(observer, "authorize-authenticated-peer",
> > > > > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > > > > +
> > > > > + server = g_dbus_server_new_sync(addr,
> > > > > + G_DBUS_SERVER_FLAGS_NONE,
> > > > > + guid,
> > > > > + observer,
> > > > > + NULL, /* GCancellable */
> > > > > + &error);
> > > > > + g_dbus_server_start(server);
> > > > > + g_clear_object(&observer);
> > > > > + g_free(guid);
> > > > > +
> > > > > + if (server == NULL) {
> > > > > + g_printerr("Error creating server at address %s: %s\n",
> > > > > + addr, error->message);
> > > > > + g_error_free(error);
> > > > > + return NULL;
> > > > > + }
> > > > > +
> > > > > + g_signal_connect(server, "new-connection",
> > > > > + G_CALLBACK(on_new_connection), h);
> > > > > +
> > > > > + g_free(addr);
> > > > > + return server;
> > > > > +}
> > > > > +
> > > > > +
> > > > > +static gpointer
> > > > > +dbus_thread(gpointer p)
> > > > > +{
> > > > > + Test *test = p;
> > > > > + GMainContext *context = g_main_context_new();
> > > > > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > > > > +
> > > > > + g_main_context_push_thread_default(context);
> > > > > +
> > > > > + g_mutex_lock(&mutex);
> > > > > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > > > > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > > > > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > > > > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > > > > + test->dbus_loop = loop;
> > > > > + g_cond_signal(&cond);
> > > > > + g_mutex_unlock(&mutex);
> > > > > +
> > > > > + g_main_loop_run(loop);
> > > > > +
> > > > > + g_main_loop_unref(loop);
> > > > > + g_main_context_unref(context);
> > > > > +
> > > > > + g_mutex_lock(&mutex);
> > > > > + g_clear_object(&test->srcA.server);
> > > > > + g_clear_object(&test->srcB.server);
> > > > > + g_clear_object(&test->dstA.server);
> > > > > + g_clear_object(&test->dstB.server);
> > > > > + g_mutex_unlock(&mutex);
> > > > > +
> > > > > + return NULL;
> > > > > +}
> > > > > +
> > > > > +static gboolean
> > > > > +wait_for_migration_complete(gpointer user_data)
> > > > > +{
> > > > > + Test *test = user_data;
> > > > > + QDict *rsp_return;
> > > > > + bool stop = false;
> > > > > + const char *status;
> > > > > +
> > > > > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > > > > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > > > > + status = qdict_get_str(rsp_return, "status");
> > > > > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > > > > + stop = true;
> > > > > + g_assert_cmpstr(status, ==,
> > > > > + test->migrate_fail ? "failed" : "completed");
> > > > > + }
> > > > > + qobject_unref(rsp_return);
> > > > > +
> > > > > + if (stop) {
> > > > > + g_main_loop_quit(test->loop);
> > > > > + }
> > > > > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > > > > +}
> > > > > +
> > > > > +static void migrate(QTestState *who, const char *uri)
> > > > > +{
> > > > > + QDict *args, *rsp;
> > > > > +
> > > > > + args = qdict_new();
> > > > > + qdict_put_str(args, "uri", uri);
> > > > > +
> > > > > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > > > > +
> > > > > + g_assert(qdict_haskey(rsp, "return"));
> > > > > + qobject_unref(rsp);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +test_dbus_vmstate(Test *test)
> > > > > +{
> > > > > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > > > > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > > > > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > > > > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > > > > +
> > > > > + g_mutex_lock(&mutex);
> > > > > + while (!test->dbus_loop) {
> > > > > + g_cond_wait(&cond, &mutex);
> > > > > + }
> > > > > +
> > > > > + src_qemu_args =
> > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > + "-object dbus-vmstate,id=dvB,addr=%s",
> > > > > + g_dbus_server_get_client_address(test->srcA.server),
> > > > > + g_dbus_server_get_client_address(test->srcB.server));
> > > > > +
> > > > > +
> > > > > + dst_qemu_args =
> > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > + "-object dbus-vmstate,id=dvB,addr=%s "
> > > > > + "-incoming %s",
> > > > > + g_dbus_server_get_client_address(test->dstA.server),
> > > > > + g_dbus_server_get_client_address(test->dstB.server),
> > > > > + uri);
> > > > > +
> > > > > + src_qemu = qtest_init(src_qemu_args);
> > > > > + dst_qemu = qtest_init(dst_qemu_args);
> > > > > +
> > > > > + test->loop = g_main_loop_new(NULL, TRUE);
> > > > > +
> > > > > + migrate(src_qemu, uri);
> > > > > + test->src_qemu = src_qemu;
> > > > > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > > > > +
> > > > > + g_main_loop_run(test->loop);
> > > > > + g_main_loop_unref(test->loop);
> > > > > +
> > > > > + g_free(uri);
> > > > > + qtest_quit(dst_qemu);
> > > > > + qtest_quit(src_qemu);
> > > > > + g_free(dst_qemu_args);
> > > > > + g_free(src_qemu_args);
> > > > > +
> > > > > + g_main_loop_quit(test->dbus_loop);
> > > > > + g_mutex_unlock(&mutex);
> > > > > +
> > > > > + g_thread_join(t);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +check_migrated(TestServer *s, TestServer *d)
> > > > > +{
> > > > > + assert(s->save_called);
> > > > > + assert(!s->load_called);
> > > > > + assert(!d->save_called);
> > > > > + assert(d->load_called);
> > > > > +}
> > > > > +
> > > > > +static void
> > > > > +test_dbus_vmstate_migrate(void)
> > > > > +{
> > > > > + Test test = { };
> > > > > +
> > > > > + test_dbus_vmstate(&test);
> > > > > +
> > > > > + check_migrated(&test.srcA, &test.dstA);
> > > > > + check_migrated(&test.srcB, &test.dstB);
> > > > > +}
> > > > > +
> > > > > +int
> > > > > +main(int argc, char **argv)
> > > > > +{
> > > > > + GError *err = NULL;
> > > > > + int ret;
> > > > > +
> > > > > + g_test_init(&argc, &argv, NULL);
> > > > > +
> > > > > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > > > > + if (!workdir) {
> > > > > + g_error("Unable to create temporary dir: %s\n", err->message);
> > > > > + }
> > > > > +
> > > > > + qtest_add_func("/dbus-vmstate/migrate",
> > > > > + test_dbus_vmstate_migrate);
> > > > > +
> > > > > + ret = g_test_run();
> > > > > +
> > > > > + rmdir(workdir);
> > > > > + g_free(workdir);
> > > > > +
> > > > > + return ret;
> > > > > +}
> > > > > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > > > > new file mode 100644
> > > > > index 0000000000..cc8563be4c
> > > > > --- /dev/null
> > > > > +++ b/tests/dbus-vmstate1.xml
> > > > > @@ -0,0 +1,12 @@
> > > > > +<?xml version="1.0"?>
> > > > > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > > > > + <interface name="org.qemu.VMState1">
> > > > > + <property name="Id" type="s" access="read"/>
> > > > > + <method name="Load">
> > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > + </method>
> > > > > + <method name="Save">
> > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > + </method>
> > > > > + </interface>
> > > > > +</node>
> > > > > --
> > > > > 2.23.0.rc1
> > > > >
> > > > --
> > > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Hi
On Thu, Aug 22, 2019 at 4:20 PM Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
>
> * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > Hi
> >
> > On Thu, Aug 22, 2019 at 3:41 PM Dr. David Alan Gilbert
> > <dgilbert@redhat.com> wrote:
> > >
> > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > Hi
> > > >
> > > > On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
> > > > <dgilbert@redhat.com> wrote:
> > > > >
> > > > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > > > When instanciated, this object will connect to the given D-Bus
> > > > > > bus. During migration, it will take the data from org.qemu.VMState1
> > > > > > instances.
> > > > > >
> > > > > > See documentation for further details.
> > > > >
> > > > > I'll leave the main review to someone who understands the details of
> > > > > DBUS, however from the migration side:
> > > > >
> > > > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > > > >
> > > > > <snip>
> > > > >
> > > > > > +
> > > > > > +static int
> > > > > > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > > + uint8_t *data = NULL;
> > > > > > + int ret = -1;
> > > > > > + char id[256];
> > > > > > + unsigned int size;
> > > > >
> > > > > Higher level question; do you actually need a separate ID, or does
> > > > > the ID that's stored by the migration code in the section name
> > > > > give you enough uniqueness?
> > > >
> > > >
> > > > The ID stored in migration section name is based on the handler ID:
> > > > TYPE_DBUS_VMSTATE "-" handler_id
> > > >
> > > > By design, handler_id must be unique (and documented as such).
> > > >
> > > > Do you see a problem with that approach?
> > >
> > > OK, so if that's unique, why do you need an 'id' stored here?
> >
> > Oh I see, that's mostly a relic of v1, where multiple ID
> > "sub-sections" would exist for each helper.
> >
> > However, if we want to allow having several "sub-sections" again, that
> > might come handy to keep compatibility. It may be better to have a
> > simple version field for that instead.
>
> OK, that's fine
>
> > >
> > > > >
> > > > > > + if (qemu_get_counted_string(f, id) == 0) {
> > > > > > + error_report("Invalid vmstate Id");
> > > > > > + goto end;
> > > > >
> > > > > I generally prefer to include something telling me where the error has
> > > > > come from, just to make it easier to track down if I see the error in
> > > > > a log; e.g. use __func__
> > > >
> > > > ok
> > > >
> > > > >
> > > > > > + }
> > > > > > +
> > > > > > + if (g_strcmp0(id, self->id)) {
> > > > > > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + size = qemu_get_be32(f);
> > > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > > + error_report("Invalid vmstate size: %u", size);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + data = g_malloc(size);
> > > > > > + if (qemu_get_buffer(f, data, size) != size) {
> > > > > > + error_report("Failed to read %u bytes", size);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > > > > > + error_report("Failed to restore Id '%s'", id);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + ret = 0;
> > > > > > +
> > > > > > +end:
> > > > > > + g_clear_pointer(&data, g_free);
> > > > > > + return ret;
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +dbus_save_state(QEMUFile *f, void *opaque)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > > + GVariant *result = NULL, *child = NULL;
> > > > > > + const uint8_t *data;
> > > > > > + size_t size;
> > > > > > + GError *err = NULL;
> > > > > > +
> > > > > > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > > > > > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > > > > > + -1, NULL, &err);
> > > > > > + if (!result) {
> > > > > > + error_report("Failed to Save: %s", err->message);
> > > > > > + g_clear_error(&err);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + child = g_variant_get_child_value(result, 0);
> > > > > > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > > > > > + if (!data) {
> > > > > > + error_report("Failed to Save: not a byte array");
> > > > > > + goto end;
> > > > > > + }
> > > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > > + error_report("Too much vmstate data to save: %zu", size);
> > > > > > + goto end;
> > > > > > + }
> > > > > > +
> > > > > > + qemu_put_counted_string(f, self->id);
> > > > > > + qemu_put_be32(f, size);
> > > > > > + qemu_put_buffer(f, data, size);
> > > > > > +
> > > > > > +end:
> > > > > > + g_clear_pointer(&child, g_variant_unref);
> > > > > > + g_clear_pointer(&result, g_variant_unref);
> > > > > > +}
> > > > > > +
> > > > > > +static const SaveVMHandlers savevm_handlers = {
> > > > > > + .save_state = dbus_save_state,
> > > > > > + .load_state = dbus_load_state,
> > > > > > +};
> > > > > > +
> > > > > > +static void
> > > > > > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(uc);
> > > > > > + GError *err = NULL;
> > > > > > + GDBusConnection *bus = NULL;
> > > > > > + GDBusProxy *proxy = NULL;
> > > > > > + char *idstr = NULL;
> > > > > > +
> > > > > > + if (!self->dbus_addr) {
> > > > > > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > > > > > + return;
> > > > > > + }
> > > > > > +
> > > > > > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > > > > > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > > > > > + NULL, NULL, &err);
> > > > > > + if (err) {
> > > > > > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > > > > > + g_clear_error(&err);
> > > > > > + return;
> > > > > > + }
> > > > > > +
> > > > > > + self->bus = bus;
> > > > > > +
> > > > > > + proxy = g_dbus_proxy_new_sync(bus,
> > > > > > + G_DBUS_PROXY_FLAGS_NONE,
> > > > > > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > > > > > + NULL,
> > > > > > + "/org/qemu/VMState1",
> > > > > > + "org.qemu.VMState1",
> > > > > > + NULL, &err);
> > > > > > +
> > > > > > + if (err) {
> > > > > > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > > > > > + g_clear_error(&err);
> > > > > > + return;
> > > > > > + }
> > > > > > +
> > > > > > + self->proxy = proxy;
> > > > > > +
> > > > > > + self->id = dbus_proxy_get_id(proxy, &err);
> > > > > > + if (!self->id) {
> > > > > > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > > > > > + g_clear_error(&err);
> > > > > > + return;
> > > > > > + }
> > > > > > +
> > > > > > + idstr = get_idstr(self);
> > > > > > + if (register_savevm_live(NULL, idstr, 0, 0,
> > > > > > + &savevm_handlers, self) < 0) {
> > > > > > + error_setg(errp, "Failed to register savevm handler");
> > > > > > + }
> > > > >
> > > > > Can you try and avoid register_savevm_live if possible and just wire a
> > > > > vmsd onto the class like most other devices? We don't have many
> > > > > register_savevm_live calls, and I'd like to get them down to just the
> > > > > iterative devices.
> > > >
> > > > Sure if I could, but it's not a device.
> > > >
> > > > Perhaps we could have a qom interface for vmsd users? I can try that eventually.
> > >
> > > Hmm, why isn't it a device?
> >
> > It doesn't need anything from Device (which is heavyweight), it is a
> > simple user-creatable object that holds a dbus connection and reacts
> > on migration events.
> >
> > If you take slirp helper process as an example, it's a "service" for a
> > VM. Not a device. You could have the same helper for various devices
> > etc, or more helpers for the same device.
>
> I think you're better calling this a device; the slirp world doesn't fit
> nicely either and it would be better if it was a device as well.
>
The goal here is to migrate helper processes along with qemu.
Helper processes may be things like slirp, network services, emulators
(such as swtpm, which isn't a device either), or long-running
jobs/process done on behalf of qemu, for example a AV compression,
spice server...
> Dave
>
> > >
> > >
> > > Dave
> > >
> > > > thanks
> > > >
> > > > > Dave
> > > > >
> > > > >
> > > > > > + g_free(idstr);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +dbus_vmstate_finalize(Object *o)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > + char *idstr = get_idstr(self);
> > > > > > +
> > > > > > + unregister_savevm(NULL, idstr, self);
> > > > > > +
> > > > > > + g_clear_object(&self->bus);
> > > > > > + g_clear_object(&self->proxy);
> > > > > > + g_free(self->dbus_addr);
> > > > > > + g_free(self->id);
> > > > > > + g_free(idstr);
> > > > > > +}
> > > > > > +
> > > > > > +static char *
> > > > > > +get_dbus_addr(Object *o, Error **errp)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > +
> > > > > > + return g_strdup(self->dbus_addr);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > > > > > +{
> > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > +
> > > > > > + g_free(self->dbus_addr);
> > > > > > + self->dbus_addr = g_strdup(str);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > > > > > +{
> > > > > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > > > > > +
> > > > > > + ucc->complete = dbus_vmstate_complete;
> > > > > > +
> > > > > > + object_class_property_add_str(oc, "addr",
> > > > > > + get_dbus_addr, set_dbus_addr,
> > > > > > + &error_abort);
> > > > > > +}
> > > > > > +
> > > > > > +static const TypeInfo dbus_vmstate_info = {
> > > > > > + .name = TYPE_DBUS_VMSTATE,
> > > > > > + .parent = TYPE_OBJECT,
> > > > > > + .instance_size = sizeof(DBusVMState),
> > > > > > + .instance_finalize = dbus_vmstate_finalize,
> > > > > > + .class_size = sizeof(DBusVMStateClass),
> > > > > > + .class_init = dbus_vmstate_class_init,
> > > > > > + .interfaces = (InterfaceInfo[]) {
> > > > > > + { TYPE_USER_CREATABLE },
> > > > > > + { }
> > > > > > + }
> > > > > > +};
> > > > > > +
> > > > > > +static void
> > > > > > +register_types(void)
> > > > > > +{
> > > > > > + type_register_static(&dbus_vmstate_info);
> > > > > > +}
> > > > > > +
> > > > > > +type_init(register_types);
> > > > > > diff --git a/configure b/configure
> > > > > > index 714e7fb6a1..e5b34f5ca7 100755
> > > > > > --- a/configure
> > > > > > +++ b/configure
> > > > > > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > > > > > gio=yes
> > > > > > gio_cflags=$($pkg_config --cflags gio-2.0)
> > > > > > gio_libs=$($pkg_config --libs gio-2.0)
> > > > > > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > > > > > else
> > > > > > gio=no
> > > > > > fi
> > > > > >
> > > > > > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > > > > > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > > > > > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > > > > > +fi
> > > > > > +
> > > > > > # Sanity check that the current size_t matches the
> > > > > > # size that glib thinks it should be. This catches
> > > > > > # problems on multi-arch where people try to build
> > > > > > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > > > > > echo "CONFIG_GIO=y" >> $config_host_mak
> > > > > > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > > > > > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > > > > > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > > > > > fi
> > > > > > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > > > > > if test "$gnutls" = "yes" ; then
> > > > > > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > > > > > new file mode 100644
> > > > > > index 0000000000..4a32a183fb
> > > > > > --- /dev/null
> > > > > > +++ b/docs/interop/dbus-vmstate.rst
> > > > > > @@ -0,0 +1,63 @@
> > > > > > +============
> > > > > > +DBus VMState
> > > > > > +============
> > > > > > +
> > > > > > +Introduction
> > > > > > +============
> > > > > > +
> > > > > > +Helper processes may have their state migrated with the help of
> > > > > > +QEMU "dbus-vmstate" objects.
> > > > > > +
> > > > > > +At this point, the connection to the helper is done in DBus
> > > > > > +peer-to-peer mode (no initial Hello, and no bus name for
> > > > > > +communication). The helper must be listening to the given address.
> > > > > > +
> > > > > > +Helper may save arbitrary data to be transferred in the migration
> > > > > > +stream and restored/loaded on destination.
> > > > > > +
> > > > > > +The data amount to be transferred is limited to 1Mb. The state must be
> > > > > > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > > > > > +reply anyway, and migration would fail if the data isn't given quickly
> > > > > > +enough)
> > > > > > +
> > > > > > +Interface
> > > > > > +=========
> > > > > > +
> > > > > > +On /org/qemu/VMState1 object path:
> > > > > > +
> > > > > > +.. code:: xml
> > > > > > +
> > > > > > + <interface name="org.qemu.VMState1">
> > > > > > + <property name="Id" type="s" access="read"/>
> > > > > > + <method name="Load">
> > > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > > + </method>
> > > > > > + <method name="Save">
> > > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > > + </method>
> > > > > > + </interface>
> > > > > > +
> > > > > > +"Id" property
> > > > > > +-------------
> > > > > > +
> > > > > > +A utf8 encoded string that identifies the helper uniquely.
> > > > > > +Must be <256 bytes.
> > > > > > +
> > > > > > +Load(in u8[] bytes) method
> > > > > > +--------------------------
> > > > > > +
> > > > > > +The method called on destination with the state to restore.
> > > > > > +
> > > > > > +The helper may be initially started in a waiting state (with
> > > > > > +an --incoming argument for example), and it may resume on load
> > > > > > +success.
> > > > > > +
> > > > > > +An error may be returned to the caller.
> > > > > > +
> > > > > > +Save(out u8[] bytes) method
> > > > > > +---------------------------
> > > > > > +
> > > > > > +The method called on the source to get the current state to be
> > > > > > +migrated. The helper should continue to run normally.
> > > > > > +
> > > > > > +An error may be returned to the caller.
> > > > > > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > > > > > index b4bfcab417..6bb173cfa6 100644
> > > > > > --- a/docs/interop/index.rst
> > > > > > +++ b/docs/interop/index.rst
> > > > > > @@ -13,6 +13,7 @@ Contents:
> > > > > > :maxdepth: 2
> > > > > >
> > > > > > bitmaps
> > > > > > + dbus-vmstate
> > > > > > live-block-operations
> > > > > > pr-helper
> > > > > > vhost-user
> > > > > > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > > > > > index fd7fdb8658..2c610086a7 100644
> > > > > > --- a/tests/Makefile.include
> > > > > > +++ b/tests/Makefile.include
> > > > > > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > > > > > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > > > > > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > > > > > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > > > > > -
> > > > > > +ifneq ($(GDBUS_CODEGEN),)
> > > > > > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > > > > > +endif
> > > > > > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > > > > > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > > > > > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > > > > > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > > > > > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > > > > > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> > > > > >
> > > > > > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > > > > > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > > > > > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > > > > > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > > > > > + "GEN","$(@:%-timestamp=%)")
> > > > > > + @>$@
> > > > > > +
> > > > > > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > > > > > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > > > > > +
> > > > > > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > > > > > +
> > > > > > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > > > > > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > > > > > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > > > > > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > > > > > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > > > > > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > > > > > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > > > > > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > > > > > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > > > > > @@ -1172,6 +1187,7 @@ check-clean:
> > > > > > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > > > > > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > > > > > rm -f tests/test-qapi-gen-timestamp
> > > > > > + rm -f tests/dbus-vmstate1-gen-timestamp
> > > > > > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> > > > > >
> > > > > > clean: check-clean
> > > > > > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > > > > > new file mode 100644
> > > > > > index 0000000000..45d44916d2
> > > > > > --- /dev/null
> > > > > > +++ b/tests/dbus-vmstate-test.c
> > > > > > @@ -0,0 +1,371 @@
> > > > > > +#include "qemu/osdep.h"
> > > > > > +#include <glib/gstdio.h>
> > > > > > +#include <gio/gio.h>
> > > > > > +#include "libqtest.h"
> > > > > > +#include "qemu-common.h"
> > > > > > +#include "dbus-vmstate1.h"
> > > > > > +
> > > > > > +static char *workdir;
> > > > > > +
> > > > > > +typedef struct TestServerId {
> > > > > > + const char *name;
> > > > > > + const char *data;
> > > > > > + size_t size;
> > > > > > +} TestServerId;
> > > > > > +
> > > > > > +static const TestServerId idA = {
> > > > > > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > > > > > +};
> > > > > > +
> > > > > > +static const TestServerId idB = {
> > > > > > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > > > > > +};
> > > > > > +
> > > > > > +typedef struct TestServer {
> > > > > > + const TestServerId *id;
> > > > > > + bool save_called;
> > > > > > + bool load_called;
> > > > > > + GDBusObjectManagerServer *om;
> > > > > > + GDBusServer *server;
> > > > > > +} TestServer;
> > > > > > +
> > > > > > +typedef struct Test {
> > > > > > + bool migrate_fail;
> > > > > > + TestServer srcA;
> > > > > > + TestServer dstA;
> > > > > > + TestServer srcB;
> > > > > > + TestServer dstB;
> > > > > > + GMainLoop *loop, *dbus_loop;
> > > > > > + QTestState *src_qemu;
> > > > > > +} Test;
> > > > > > +
> > > > > > +GMutex mutex;
> > > > > > +GCond cond;
> > > > > > +
> > > > > > +static gboolean
> > > > > > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > > + const gchar *arg_data, gpointer user_data)
> > > > > > +{
> > > > > > + TestServer *h = user_data;
> > > > > > + GVariant *args, *var;
> > > > > > + const uint8_t *data;
> > > > > > + size_t size;
> > > > > > +
> > > > > > + args = g_dbus_method_invocation_get_parameters(invocation);
> > > > > > + var = g_variant_get_child_value(args, 0);
> > > > > > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > > > > > + g_assert_cmpuint(size, ==, h->id->size);
> > > > > > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > > > > > + h->load_called = true;
> > > > > > + g_variant_unref(var);
> > > > > > +
> > > > > > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > > > > > + return TRUE;
> > > > > > +}
> > > > > > +
> > > > > > +static gboolean
> > > > > > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > > + gpointer user_data)
> > > > > > +{
> > > > > > + TestServer *h = user_data;
> > > > > > + GVariant *var;
> > > > > > +
> > > > > > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > > > > > + h->id->data, h->id->size, sizeof(char));
> > > > > > + g_dbus_method_invocation_return_value(invocation,
> > > > > > + g_variant_new("(@ay)", var));
> > > > > > + h->save_called = true;
> > > > > > +
> > > > > > + return TRUE;
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +connection_closed(GDBusConnection *connection,
> > > > > > + gboolean remote_peer_vanished,
> > > > > > + GError *Error,
> > > > > > + gpointer user_data)
> > > > > > +{
> > > > > > + TestServer *h = user_data;
> > > > > > +
> > > > > > + g_clear_object(&h->om);
> > > > > > + g_clear_object(&connection);
> > > > > > +}
> > > > > > +
> > > > > > +static GDBusObjectManagerServer *
> > > > > > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > > > > > +{
> > > > > > + TestServer *h = user_data;
> > > > > > + GDBusObjectManagerServer *om;
> > > > > > + GDBusObjectSkeleton *sk;
> > > > > > + VMState1 *v;
> > > > > > +
> > > > > > + om = g_dbus_object_manager_server_new("/org/qemu");
> > > > > > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > > > > > +
> > > > > > + v = vmstate1_skeleton_new();
> > > > > > + g_object_set(v, "id", h->id->name, NULL);
> > > > > > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > > > > > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > > > > > +
> > > > > > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > > > > > + g_dbus_object_manager_server_export(om, sk);
> > > > > > + g_dbus_object_manager_server_set_connection(om, conn);
> > > > > > +
> > > > > > + g_clear_object(&v);
> > > > > > + g_clear_object(&sk);
> > > > > > +
> > > > > > + return om;
> > > > > > +}
> > > > > > +
> > > > > > +static gboolean
> > > > > > +on_new_connection(GDBusServer *server,
> > > > > > + GDBusConnection *connection,
> > > > > > + gpointer user_data)
> > > > > > +{
> > > > > > + TestServer *h = user_data;
> > > > > > +
> > > > > > + g_object_ref(connection);
> > > > > > + g_signal_connect(connection, "closed",
> > > > > > + G_CALLBACK(connection_closed), user_data);
> > > > > > + h->om = get_omserver(connection, user_data);
> > > > > > +
> > > > > > + return TRUE;
> > > > > > +}
> > > > > > +
> > > > > > +static gboolean
> > > > > > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > > > > > + const gchar *mechanism,
> > > > > > + gpointer user_data)
> > > > > > +{
> > > > > > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > > > > > +}
> > > > > > +
> > > > > > +static gboolean
> > > > > > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > > > > > + GIOStream *stream,
> > > > > > + GCredentials *credentials,
> > > > > > + gpointer user_data)
> > > > > > +{
> > > > > > + gboolean authorized = FALSE;
> > > > > > +
> > > > > > + if (credentials != NULL) {
> > > > > > + GCredentials *own_credentials = g_credentials_new();
> > > > > > +
> > > > > > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > > > > > + authorized = TRUE;
> > > > > > + }
> > > > > > +
> > > > > > + g_clear_object(&own_credentials);
> > > > > > + }
> > > > > > +
> > > > > > + return authorized;
> > > > > > +}
> > > > > > +
> > > > > > +static GDBusServer *
> > > > > > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > > > > > +{
> > > > > > + GDBusAuthObserver *observer = NULL;
> > > > > > + GDBusServer *server = NULL;
> > > > > > + gchar *guid = NULL;
> > > > > > + GError *error = NULL;
> > > > > > + char *addr = NULL;
> > > > > > +
> > > > > > + h->id = id;
> > > > > > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > > > > > + guid = g_dbus_generate_guid();
> > > > > > + observer = g_dbus_auth_observer_new();
> > > > > > + g_signal_connect(observer, "allow-mechanism",
> > > > > > + G_CALLBACK(allow_mechanism_cb), h);
> > > > > > + g_signal_connect(observer, "authorize-authenticated-peer",
> > > > > > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > > > > > +
> > > > > > + server = g_dbus_server_new_sync(addr,
> > > > > > + G_DBUS_SERVER_FLAGS_NONE,
> > > > > > + guid,
> > > > > > + observer,
> > > > > > + NULL, /* GCancellable */
> > > > > > + &error);
> > > > > > + g_dbus_server_start(server);
> > > > > > + g_clear_object(&observer);
> > > > > > + g_free(guid);
> > > > > > +
> > > > > > + if (server == NULL) {
> > > > > > + g_printerr("Error creating server at address %s: %s\n",
> > > > > > + addr, error->message);
> > > > > > + g_error_free(error);
> > > > > > + return NULL;
> > > > > > + }
> > > > > > +
> > > > > > + g_signal_connect(server, "new-connection",
> > > > > > + G_CALLBACK(on_new_connection), h);
> > > > > > +
> > > > > > + g_free(addr);
> > > > > > + return server;
> > > > > > +}
> > > > > > +
> > > > > > +
> > > > > > +static gpointer
> > > > > > +dbus_thread(gpointer p)
> > > > > > +{
> > > > > > + Test *test = p;
> > > > > > + GMainContext *context = g_main_context_new();
> > > > > > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > > > > > +
> > > > > > + g_main_context_push_thread_default(context);
> > > > > > +
> > > > > > + g_mutex_lock(&mutex);
> > > > > > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > > > > > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > > > > > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > > > > > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > > > > > + test->dbus_loop = loop;
> > > > > > + g_cond_signal(&cond);
> > > > > > + g_mutex_unlock(&mutex);
> > > > > > +
> > > > > > + g_main_loop_run(loop);
> > > > > > +
> > > > > > + g_main_loop_unref(loop);
> > > > > > + g_main_context_unref(context);
> > > > > > +
> > > > > > + g_mutex_lock(&mutex);
> > > > > > + g_clear_object(&test->srcA.server);
> > > > > > + g_clear_object(&test->srcB.server);
> > > > > > + g_clear_object(&test->dstA.server);
> > > > > > + g_clear_object(&test->dstB.server);
> > > > > > + g_mutex_unlock(&mutex);
> > > > > > +
> > > > > > + return NULL;
> > > > > > +}
> > > > > > +
> > > > > > +static gboolean
> > > > > > +wait_for_migration_complete(gpointer user_data)
> > > > > > +{
> > > > > > + Test *test = user_data;
> > > > > > + QDict *rsp_return;
> > > > > > + bool stop = false;
> > > > > > + const char *status;
> > > > > > +
> > > > > > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > > > > > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > > > > > + status = qdict_get_str(rsp_return, "status");
> > > > > > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > > > > > + stop = true;
> > > > > > + g_assert_cmpstr(status, ==,
> > > > > > + test->migrate_fail ? "failed" : "completed");
> > > > > > + }
> > > > > > + qobject_unref(rsp_return);
> > > > > > +
> > > > > > + if (stop) {
> > > > > > + g_main_loop_quit(test->loop);
> > > > > > + }
> > > > > > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > > > > > +}
> > > > > > +
> > > > > > +static void migrate(QTestState *who, const char *uri)
> > > > > > +{
> > > > > > + QDict *args, *rsp;
> > > > > > +
> > > > > > + args = qdict_new();
> > > > > > + qdict_put_str(args, "uri", uri);
> > > > > > +
> > > > > > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > > > > > +
> > > > > > + g_assert(qdict_haskey(rsp, "return"));
> > > > > > + qobject_unref(rsp);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +test_dbus_vmstate(Test *test)
> > > > > > +{
> > > > > > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > > > > > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > > > > > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > > > > > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > > > > > +
> > > > > > + g_mutex_lock(&mutex);
> > > > > > + while (!test->dbus_loop) {
> > > > > > + g_cond_wait(&cond, &mutex);
> > > > > > + }
> > > > > > +
> > > > > > + src_qemu_args =
> > > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > > + "-object dbus-vmstate,id=dvB,addr=%s",
> > > > > > + g_dbus_server_get_client_address(test->srcA.server),
> > > > > > + g_dbus_server_get_client_address(test->srcB.server));
> > > > > > +
> > > > > > +
> > > > > > + dst_qemu_args =
> > > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > > + "-object dbus-vmstate,id=dvB,addr=%s "
> > > > > > + "-incoming %s",
> > > > > > + g_dbus_server_get_client_address(test->dstA.server),
> > > > > > + g_dbus_server_get_client_address(test->dstB.server),
> > > > > > + uri);
> > > > > > +
> > > > > > + src_qemu = qtest_init(src_qemu_args);
> > > > > > + dst_qemu = qtest_init(dst_qemu_args);
> > > > > > +
> > > > > > + test->loop = g_main_loop_new(NULL, TRUE);
> > > > > > +
> > > > > > + migrate(src_qemu, uri);
> > > > > > + test->src_qemu = src_qemu;
> > > > > > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > > > > > +
> > > > > > + g_main_loop_run(test->loop);
> > > > > > + g_main_loop_unref(test->loop);
> > > > > > +
> > > > > > + g_free(uri);
> > > > > > + qtest_quit(dst_qemu);
> > > > > > + qtest_quit(src_qemu);
> > > > > > + g_free(dst_qemu_args);
> > > > > > + g_free(src_qemu_args);
> > > > > > +
> > > > > > + g_main_loop_quit(test->dbus_loop);
> > > > > > + g_mutex_unlock(&mutex);
> > > > > > +
> > > > > > + g_thread_join(t);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +check_migrated(TestServer *s, TestServer *d)
> > > > > > +{
> > > > > > + assert(s->save_called);
> > > > > > + assert(!s->load_called);
> > > > > > + assert(!d->save_called);
> > > > > > + assert(d->load_called);
> > > > > > +}
> > > > > > +
> > > > > > +static void
> > > > > > +test_dbus_vmstate_migrate(void)
> > > > > > +{
> > > > > > + Test test = { };
> > > > > > +
> > > > > > + test_dbus_vmstate(&test);
> > > > > > +
> > > > > > + check_migrated(&test.srcA, &test.dstA);
> > > > > > + check_migrated(&test.srcB, &test.dstB);
> > > > > > +}
> > > > > > +
> > > > > > +int
> > > > > > +main(int argc, char **argv)
> > > > > > +{
> > > > > > + GError *err = NULL;
> > > > > > + int ret;
> > > > > > +
> > > > > > + g_test_init(&argc, &argv, NULL);
> > > > > > +
> > > > > > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > > > > > + if (!workdir) {
> > > > > > + g_error("Unable to create temporary dir: %s\n", err->message);
> > > > > > + }
> > > > > > +
> > > > > > + qtest_add_func("/dbus-vmstate/migrate",
> > > > > > + test_dbus_vmstate_migrate);
> > > > > > +
> > > > > > + ret = g_test_run();
> > > > > > +
> > > > > > + rmdir(workdir);
> > > > > > + g_free(workdir);
> > > > > > +
> > > > > > + return ret;
> > > > > > +}
> > > > > > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > > > > > new file mode 100644
> > > > > > index 0000000000..cc8563be4c
> > > > > > --- /dev/null
> > > > > > +++ b/tests/dbus-vmstate1.xml
> > > > > > @@ -0,0 +1,12 @@
> > > > > > +<?xml version="1.0"?>
> > > > > > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > > > > > + <interface name="org.qemu.VMState1">
> > > > > > + <property name="Id" type="s" access="read"/>
> > > > > > + <method name="Load">
> > > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > > + </method>
> > > > > > + <method name="Save">
> > > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > > + </method>
> > > > > > + </interface>
> > > > > > +</node>
> > > > > > --
> > > > > > 2.23.0.rc1
> > > > > >
> > > > > --
> > > > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > > --
> > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
--
Marc-André Lureau
* Marc-André Lureau (marcandre.lureau@gmail.com) wrote:
> Hi
>
> On Thu, Aug 22, 2019 at 4:20 PM Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> >
> > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > Hi
> > >
> > > On Thu, Aug 22, 2019 at 3:41 PM Dr. David Alan Gilbert
> > > <dgilbert@redhat.com> wrote:
> > > >
> > > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > > Hi
> > > > >
> > > > > On Thu, Aug 22, 2019 at 2:56 PM Dr. David Alan Gilbert
> > > > > <dgilbert@redhat.com> wrote:
> > > > > >
> > > > > > * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > > > > > > When instanciated, this object will connect to the given D-Bus
> > > > > > > bus. During migration, it will take the data from org.qemu.VMState1
> > > > > > > instances.
> > > > > > >
> > > > > > > See documentation for further details.
> > > > > >
> > > > > > I'll leave the main review to someone who understands the details of
> > > > > > DBUS, however from the migration side:
> > > > > >
> > > > > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > > > > >
> > > > > > <snip>
> > > > > >
> > > > > > > +
> > > > > > > +static int
> > > > > > > +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > > > + uint8_t *data = NULL;
> > > > > > > + int ret = -1;
> > > > > > > + char id[256];
> > > > > > > + unsigned int size;
> > > > > >
> > > > > > Higher level question; do you actually need a separate ID, or does
> > > > > > the ID that's stored by the migration code in the section name
> > > > > > give you enough uniqueness?
> > > > >
> > > > >
> > > > > The ID stored in migration section name is based on the handler ID:
> > > > > TYPE_DBUS_VMSTATE "-" handler_id
> > > > >
> > > > > By design, handler_id must be unique (and documented as such).
> > > > >
> > > > > Do you see a problem with that approach?
> > > >
> > > > OK, so if that's unique, why do you need an 'id' stored here?
> > >
> > > Oh I see, that's mostly a relic of v1, where multiple ID
> > > "sub-sections" would exist for each helper.
> > >
> > > However, if we want to allow having several "sub-sections" again, that
> > > might come handy to keep compatibility. It may be better to have a
> > > simple version field for that instead.
> >
> > OK, that's fine
> >
> > > >
> > > > > >
> > > > > > > + if (qemu_get_counted_string(f, id) == 0) {
> > > > > > > + error_report("Invalid vmstate Id");
> > > > > > > + goto end;
> > > > > >
> > > > > > I generally prefer to include something telling me where the error has
> > > > > > come from, just to make it easier to track down if I see the error in
> > > > > > a log; e.g. use __func__
> > > > >
> > > > > ok
> > > > >
> > > > > >
> > > > > > > + }
> > > > > > > +
> > > > > > > + if (g_strcmp0(id, self->id)) {
> > > > > > > + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + size = qemu_get_be32(f);
> > > > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > > > + error_report("Invalid vmstate size: %u", size);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + data = g_malloc(size);
> > > > > > > + if (qemu_get_buffer(f, data, size) != size) {
> > > > > > > + error_report("Failed to read %u bytes", size);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> > > > > > > + error_report("Failed to restore Id '%s'", id);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + ret = 0;
> > > > > > > +
> > > > > > > +end:
> > > > > > > + g_clear_pointer(&data, g_free);
> > > > > > > + return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +dbus_save_state(QEMUFile *f, void *opaque)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(opaque);
> > > > > > > + GVariant *result = NULL, *child = NULL;
> > > > > > > + const uint8_t *data;
> > > > > > > + size_t size;
> > > > > > > + GError *err = NULL;
> > > > > > > +
> > > > > > > + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> > > > > > > + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> > > > > > > + -1, NULL, &err);
> > > > > > > + if (!result) {
> > > > > > > + error_report("Failed to Save: %s", err->message);
> > > > > > > + g_clear_error(&err);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + child = g_variant_get_child_value(result, 0);
> > > > > > > + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> > > > > > > + if (!data) {
> > > > > > > + error_report("Failed to Save: not a byte array");
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> > > > > > > + error_report("Too much vmstate data to save: %zu", size);
> > > > > > > + goto end;
> > > > > > > + }
> > > > > > > +
> > > > > > > + qemu_put_counted_string(f, self->id);
> > > > > > > + qemu_put_be32(f, size);
> > > > > > > + qemu_put_buffer(f, data, size);
> > > > > > > +
> > > > > > > +end:
> > > > > > > + g_clear_pointer(&child, g_variant_unref);
> > > > > > > + g_clear_pointer(&result, g_variant_unref);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static const SaveVMHandlers savevm_handlers = {
> > > > > > > + .save_state = dbus_save_state,
> > > > > > > + .load_state = dbus_load_state,
> > > > > > > +};
> > > > > > > +
> > > > > > > +static void
> > > > > > > +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(uc);
> > > > > > > + GError *err = NULL;
> > > > > > > + GDBusConnection *bus = NULL;
> > > > > > > + GDBusProxy *proxy = NULL;
> > > > > > > + char *idstr = NULL;
> > > > > > > +
> > > > > > > + if (!self->dbus_addr) {
> > > > > > > + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> > > > > > > + return;
> > > > > > > + }
> > > > > > > +
> > > > > > > + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> > > > > > > + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> > > > > > > + NULL, NULL, &err);
> > > > > > > + if (err) {
> > > > > > > + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> > > > > > > + g_clear_error(&err);
> > > > > > > + return;
> > > > > > > + }
> > > > > > > +
> > > > > > > + self->bus = bus;
> > > > > > > +
> > > > > > > + proxy = g_dbus_proxy_new_sync(bus,
> > > > > > > + G_DBUS_PROXY_FLAGS_NONE,
> > > > > > > + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> > > > > > > + NULL,
> > > > > > > + "/org/qemu/VMState1",
> > > > > > > + "org.qemu.VMState1",
> > > > > > > + NULL, &err);
> > > > > > > +
> > > > > > > + if (err) {
> > > > > > > + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> > > > > > > + g_clear_error(&err);
> > > > > > > + return;
> > > > > > > + }
> > > > > > > +
> > > > > > > + self->proxy = proxy;
> > > > > > > +
> > > > > > > + self->id = dbus_proxy_get_id(proxy, &err);
> > > > > > > + if (!self->id) {
> > > > > > > + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> > > > > > > + g_clear_error(&err);
> > > > > > > + return;
> > > > > > > + }
> > > > > > > +
> > > > > > > + idstr = get_idstr(self);
> > > > > > > + if (register_savevm_live(NULL, idstr, 0, 0,
> > > > > > > + &savevm_handlers, self) < 0) {
> > > > > > > + error_setg(errp, "Failed to register savevm handler");
> > > > > > > + }
> > > > > >
> > > > > > Can you try and avoid register_savevm_live if possible and just wire a
> > > > > > vmsd onto the class like most other devices? We don't have many
> > > > > > register_savevm_live calls, and I'd like to get them down to just the
> > > > > > iterative devices.
> > > > >
> > > > > Sure if I could, but it's not a device.
> > > > >
> > > > > Perhaps we could have a qom interface for vmsd users? I can try that eventually.
> > > >
> > > > Hmm, why isn't it a device?
> > >
> > > It doesn't need anything from Device (which is heavyweight), it is a
> > > simple user-creatable object that holds a dbus connection and reacts
> > > on migration events.
> > >
> > > If you take slirp helper process as an example, it's a "service" for a
> > > VM. Not a device. You could have the same helper for various devices
> > > etc, or more helpers for the same device.
> >
> > I think you're better calling this a device; the slirp world doesn't fit
> > nicely either and it would be better if it was a device as well.
> >
>
> The goal here is to migrate helper processes along with qemu.
>
> Helper processes may be things like slirp, network services, emulators
> (such as swtpm, which isn't a device either), or long-running
> jobs/process done on behalf of qemu, for example a AV compression,
> spice server...
So I think either fix qom to wire vmstate up, or just wear some special
glasses and see that they're really devices.
Dave
> > Dave
> >
> > > >
> > > >
> > > > Dave
> > > >
> > > > > thanks
> > > > >
> > > > > > Dave
> > > > > >
> > > > > >
> > > > > > > + g_free(idstr);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +dbus_vmstate_finalize(Object *o)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > > + char *idstr = get_idstr(self);
> > > > > > > +
> > > > > > > + unregister_savevm(NULL, idstr, self);
> > > > > > > +
> > > > > > > + g_clear_object(&self->bus);
> > > > > > > + g_clear_object(&self->proxy);
> > > > > > > + g_free(self->dbus_addr);
> > > > > > > + g_free(self->id);
> > > > > > > + g_free(idstr);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static char *
> > > > > > > +get_dbus_addr(Object *o, Error **errp)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > > +
> > > > > > > + return g_strdup(self->dbus_addr);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +set_dbus_addr(Object *o, const char *str, Error **errp)
> > > > > > > +{
> > > > > > > + DBusVMState *self = DBUS_VMSTATE(o);
> > > > > > > +
> > > > > > > + g_free(self->dbus_addr);
> > > > > > > + self->dbus_addr = g_strdup(str);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> > > > > > > +{
> > > > > > > + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> > > > > > > +
> > > > > > > + ucc->complete = dbus_vmstate_complete;
> > > > > > > +
> > > > > > > + object_class_property_add_str(oc, "addr",
> > > > > > > + get_dbus_addr, set_dbus_addr,
> > > > > > > + &error_abort);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static const TypeInfo dbus_vmstate_info = {
> > > > > > > + .name = TYPE_DBUS_VMSTATE,
> > > > > > > + .parent = TYPE_OBJECT,
> > > > > > > + .instance_size = sizeof(DBusVMState),
> > > > > > > + .instance_finalize = dbus_vmstate_finalize,
> > > > > > > + .class_size = sizeof(DBusVMStateClass),
> > > > > > > + .class_init = dbus_vmstate_class_init,
> > > > > > > + .interfaces = (InterfaceInfo[]) {
> > > > > > > + { TYPE_USER_CREATABLE },
> > > > > > > + { }
> > > > > > > + }
> > > > > > > +};
> > > > > > > +
> > > > > > > +static void
> > > > > > > +register_types(void)
> > > > > > > +{
> > > > > > > + type_register_static(&dbus_vmstate_info);
> > > > > > > +}
> > > > > > > +
> > > > > > > +type_init(register_types);
> > > > > > > diff --git a/configure b/configure
> > > > > > > index 714e7fb6a1..e5b34f5ca7 100755
> > > > > > > --- a/configure
> > > > > > > +++ b/configure
> > > > > > > @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> > > > > > > gio=yes
> > > > > > > gio_cflags=$($pkg_config --cflags gio-2.0)
> > > > > > > gio_libs=$($pkg_config --libs gio-2.0)
> > > > > > > + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> > > > > > > else
> > > > > > > gio=no
> > > > > > > fi
> > > > > > >
> > > > > > > +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> > > > > > > + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> > > > > > > + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> > > > > > > +fi
> > > > > > > +
> > > > > > > # Sanity check that the current size_t matches the
> > > > > > > # size that glib thinks it should be. This catches
> > > > > > > # problems on multi-arch where people try to build
> > > > > > > @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> > > > > > > echo "CONFIG_GIO=y" >> $config_host_mak
> > > > > > > echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> > > > > > > echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> > > > > > > + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> > > > > > > fi
> > > > > > > echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> > > > > > > if test "$gnutls" = "yes" ; then
> > > > > > > diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> > > > > > > new file mode 100644
> > > > > > > index 0000000000..4a32a183fb
> > > > > > > --- /dev/null
> > > > > > > +++ b/docs/interop/dbus-vmstate.rst
> > > > > > > @@ -0,0 +1,63 @@
> > > > > > > +============
> > > > > > > +DBus VMState
> > > > > > > +============
> > > > > > > +
> > > > > > > +Introduction
> > > > > > > +============
> > > > > > > +
> > > > > > > +Helper processes may have their state migrated with the help of
> > > > > > > +QEMU "dbus-vmstate" objects.
> > > > > > > +
> > > > > > > +At this point, the connection to the helper is done in DBus
> > > > > > > +peer-to-peer mode (no initial Hello, and no bus name for
> > > > > > > +communication). The helper must be listening to the given address.
> > > > > > > +
> > > > > > > +Helper may save arbitrary data to be transferred in the migration
> > > > > > > +stream and restored/loaded on destination.
> > > > > > > +
> > > > > > > +The data amount to be transferred is limited to 1Mb. The state must be
> > > > > > > +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> > > > > > > +reply anyway, and migration would fail if the data isn't given quickly
> > > > > > > +enough)
> > > > > > > +
> > > > > > > +Interface
> > > > > > > +=========
> > > > > > > +
> > > > > > > +On /org/qemu/VMState1 object path:
> > > > > > > +
> > > > > > > +.. code:: xml
> > > > > > > +
> > > > > > > + <interface name="org.qemu.VMState1">
> > > > > > > + <property name="Id" type="s" access="read"/>
> > > > > > > + <method name="Load">
> > > > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > > > + </method>
> > > > > > > + <method name="Save">
> > > > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > > > + </method>
> > > > > > > + </interface>
> > > > > > > +
> > > > > > > +"Id" property
> > > > > > > +-------------
> > > > > > > +
> > > > > > > +A utf8 encoded string that identifies the helper uniquely.
> > > > > > > +Must be <256 bytes.
> > > > > > > +
> > > > > > > +Load(in u8[] bytes) method
> > > > > > > +--------------------------
> > > > > > > +
> > > > > > > +The method called on destination with the state to restore.
> > > > > > > +
> > > > > > > +The helper may be initially started in a waiting state (with
> > > > > > > +an --incoming argument for example), and it may resume on load
> > > > > > > +success.
> > > > > > > +
> > > > > > > +An error may be returned to the caller.
> > > > > > > +
> > > > > > > +Save(out u8[] bytes) method
> > > > > > > +---------------------------
> > > > > > > +
> > > > > > > +The method called on the source to get the current state to be
> > > > > > > +migrated. The helper should continue to run normally.
> > > > > > > +
> > > > > > > +An error may be returned to the caller.
> > > > > > > diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> > > > > > > index b4bfcab417..6bb173cfa6 100644
> > > > > > > --- a/docs/interop/index.rst
> > > > > > > +++ b/docs/interop/index.rst
> > > > > > > @@ -13,6 +13,7 @@ Contents:
> > > > > > > :maxdepth: 2
> > > > > > >
> > > > > > > bitmaps
> > > > > > > + dbus-vmstate
> > > > > > > live-block-operations
> > > > > > > pr-helper
> > > > > > > vhost-user
> > > > > > > diff --git a/tests/Makefile.include b/tests/Makefile.include
> > > > > > > index fd7fdb8658..2c610086a7 100644
> > > > > > > --- a/tests/Makefile.include
> > > > > > > +++ b/tests/Makefile.include
> > > > > > > @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> > > > > > > check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> > > > > > > check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> > > > > > > check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> > > > > > > -
> > > > > > > +ifneq ($(GDBUS_CODEGEN),)
> > > > > > > +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> > > > > > > +endif
> > > > > > > check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> > > > > > > check-qtest-i386-y += tests/fdc-test$(EXESUF)
> > > > > > > check-qtest-i386-y += tests/ide-test$(EXESUF)
> > > > > > > @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> > > > > > > @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> > > > > > > @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
> > > > > > >
> > > > > > > +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> > > > > > > +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> > > > > > > + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> > > > > > > + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> > > > > > > + "GEN","$(@:%-timestamp=%)")
> > > > > > > + @>$@
> > > > > > > +
> > > > > > > +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> > > > > > > +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> > > > > > > +
> > > > > > > +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> > > > > > > +
> > > > > > > tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> > > > > > > tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> > > > > > > tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> > > > > > > @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> > > > > > > tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> > > > > > > tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> > > > > > > tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > > > +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> > > > > > > tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> > > > > > > tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> > > > > > > tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> > > > > > > @@ -1172,6 +1187,7 @@ check-clean:
> > > > > > > rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> > > > > > > rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> > > > > > > rm -f tests/test-qapi-gen-timestamp
> > > > > > > + rm -f tests/dbus-vmstate1-gen-timestamp
> > > > > > > rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
> > > > > > >
> > > > > > > clean: check-clean
> > > > > > > diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> > > > > > > new file mode 100644
> > > > > > > index 0000000000..45d44916d2
> > > > > > > --- /dev/null
> > > > > > > +++ b/tests/dbus-vmstate-test.c
> > > > > > > @@ -0,0 +1,371 @@
> > > > > > > +#include "qemu/osdep.h"
> > > > > > > +#include <glib/gstdio.h>
> > > > > > > +#include <gio/gio.h>
> > > > > > > +#include "libqtest.h"
> > > > > > > +#include "qemu-common.h"
> > > > > > > +#include "dbus-vmstate1.h"
> > > > > > > +
> > > > > > > +static char *workdir;
> > > > > > > +
> > > > > > > +typedef struct TestServerId {
> > > > > > > + const char *name;
> > > > > > > + const char *data;
> > > > > > > + size_t size;
> > > > > > > +} TestServerId;
> > > > > > > +
> > > > > > > +static const TestServerId idA = {
> > > > > > > + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> > > > > > > +};
> > > > > > > +
> > > > > > > +static const TestServerId idB = {
> > > > > > > + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> > > > > > > +};
> > > > > > > +
> > > > > > > +typedef struct TestServer {
> > > > > > > + const TestServerId *id;
> > > > > > > + bool save_called;
> > > > > > > + bool load_called;
> > > > > > > + GDBusObjectManagerServer *om;
> > > > > > > + GDBusServer *server;
> > > > > > > +} TestServer;
> > > > > > > +
> > > > > > > +typedef struct Test {
> > > > > > > + bool migrate_fail;
> > > > > > > + TestServer srcA;
> > > > > > > + TestServer dstA;
> > > > > > > + TestServer srcB;
> > > > > > > + TestServer dstB;
> > > > > > > + GMainLoop *loop, *dbus_loop;
> > > > > > > + QTestState *src_qemu;
> > > > > > > +} Test;
> > > > > > > +
> > > > > > > +GMutex mutex;
> > > > > > > +GCond cond;
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > > > + const gchar *arg_data, gpointer user_data)
> > > > > > > +{
> > > > > > > + TestServer *h = user_data;
> > > > > > > + GVariant *args, *var;
> > > > > > > + const uint8_t *data;
> > > > > > > + size_t size;
> > > > > > > +
> > > > > > > + args = g_dbus_method_invocation_get_parameters(invocation);
> > > > > > > + var = g_variant_get_child_value(args, 0);
> > > > > > > + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> > > > > > > + g_assert_cmpuint(size, ==, h->id->size);
> > > > > > > + g_assert(!memcmp(data, h->id->data, h->id->size));
> > > > > > > + h->load_called = true;
> > > > > > > + g_variant_unref(var);
> > > > > > > +
> > > > > > > + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> > > > > > > + return TRUE;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> > > > > > > + gpointer user_data)
> > > > > > > +{
> > > > > > > + TestServer *h = user_data;
> > > > > > > + GVariant *var;
> > > > > > > +
> > > > > > > + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> > > > > > > + h->id->data, h->id->size, sizeof(char));
> > > > > > > + g_dbus_method_invocation_return_value(invocation,
> > > > > > > + g_variant_new("(@ay)", var));
> > > > > > > + h->save_called = true;
> > > > > > > +
> > > > > > > + return TRUE;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +connection_closed(GDBusConnection *connection,
> > > > > > > + gboolean remote_peer_vanished,
> > > > > > > + GError *Error,
> > > > > > > + gpointer user_data)
> > > > > > > +{
> > > > > > > + TestServer *h = user_data;
> > > > > > > +
> > > > > > > + g_clear_object(&h->om);
> > > > > > > + g_clear_object(&connection);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static GDBusObjectManagerServer *
> > > > > > > +get_omserver(GDBusConnection *conn, gpointer user_data)
> > > > > > > +{
> > > > > > > + TestServer *h = user_data;
> > > > > > > + GDBusObjectManagerServer *om;
> > > > > > > + GDBusObjectSkeleton *sk;
> > > > > > > + VMState1 *v;
> > > > > > > +
> > > > > > > + om = g_dbus_object_manager_server_new("/org/qemu");
> > > > > > > + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> > > > > > > +
> > > > > > > + v = vmstate1_skeleton_new();
> > > > > > > + g_object_set(v, "id", h->id->name, NULL);
> > > > > > > + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> > > > > > > + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> > > > > > > +
> > > > > > > + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> > > > > > > + g_dbus_object_manager_server_export(om, sk);
> > > > > > > + g_dbus_object_manager_server_set_connection(om, conn);
> > > > > > > +
> > > > > > > + g_clear_object(&v);
> > > > > > > + g_clear_object(&sk);
> > > > > > > +
> > > > > > > + return om;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +on_new_connection(GDBusServer *server,
> > > > > > > + GDBusConnection *connection,
> > > > > > > + gpointer user_data)
> > > > > > > +{
> > > > > > > + TestServer *h = user_data;
> > > > > > > +
> > > > > > > + g_object_ref(connection);
> > > > > > > + g_signal_connect(connection, "closed",
> > > > > > > + G_CALLBACK(connection_closed), user_data);
> > > > > > > + h->om = get_omserver(connection, user_data);
> > > > > > > +
> > > > > > > + return TRUE;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +allow_mechanism_cb(GDBusAuthObserver *observer,
> > > > > > > + const gchar *mechanism,
> > > > > > > + gpointer user_data)
> > > > > > > +{
> > > > > > > + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> > > > > > > + GIOStream *stream,
> > > > > > > + GCredentials *credentials,
> > > > > > > + gpointer user_data)
> > > > > > > +{
> > > > > > > + gboolean authorized = FALSE;
> > > > > > > +
> > > > > > > + if (credentials != NULL) {
> > > > > > > + GCredentials *own_credentials = g_credentials_new();
> > > > > > > +
> > > > > > > + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> > > > > > > + authorized = TRUE;
> > > > > > > + }
> > > > > > > +
> > > > > > > + g_clear_object(&own_credentials);
> > > > > > > + }
> > > > > > > +
> > > > > > > + return authorized;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static GDBusServer *
> > > > > > > +server_start(TestServer *h, const char *p, const TestServerId *id)
> > > > > > > +{
> > > > > > > + GDBusAuthObserver *observer = NULL;
> > > > > > > + GDBusServer *server = NULL;
> > > > > > > + gchar *guid = NULL;
> > > > > > > + GError *error = NULL;
> > > > > > > + char *addr = NULL;
> > > > > > > +
> > > > > > > + h->id = id;
> > > > > > > + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> > > > > > > + guid = g_dbus_generate_guid();
> > > > > > > + observer = g_dbus_auth_observer_new();
> > > > > > > + g_signal_connect(observer, "allow-mechanism",
> > > > > > > + G_CALLBACK(allow_mechanism_cb), h);
> > > > > > > + g_signal_connect(observer, "authorize-authenticated-peer",
> > > > > > > + G_CALLBACK(authorize_authenticated_peer_cb), h);
> > > > > > > +
> > > > > > > + server = g_dbus_server_new_sync(addr,
> > > > > > > + G_DBUS_SERVER_FLAGS_NONE,
> > > > > > > + guid,
> > > > > > > + observer,
> > > > > > > + NULL, /* GCancellable */
> > > > > > > + &error);
> > > > > > > + g_dbus_server_start(server);
> > > > > > > + g_clear_object(&observer);
> > > > > > > + g_free(guid);
> > > > > > > +
> > > > > > > + if (server == NULL) {
> > > > > > > + g_printerr("Error creating server at address %s: %s\n",
> > > > > > > + addr, error->message);
> > > > > > > + g_error_free(error);
> > > > > > > + return NULL;
> > > > > > > + }
> > > > > > > +
> > > > > > > + g_signal_connect(server, "new-connection",
> > > > > > > + G_CALLBACK(on_new_connection), h);
> > > > > > > +
> > > > > > > + g_free(addr);
> > > > > > > + return server;
> > > > > > > +}
> > > > > > > +
> > > > > > > +
> > > > > > > +static gpointer
> > > > > > > +dbus_thread(gpointer p)
> > > > > > > +{
> > > > > > > + Test *test = p;
> > > > > > > + GMainContext *context = g_main_context_new();
> > > > > > > + GMainLoop *loop = g_main_loop_new(context, FALSE);
> > > > > > > +
> > > > > > > + g_main_context_push_thread_default(context);
> > > > > > > +
> > > > > > > + g_mutex_lock(&mutex);
> > > > > > > + test->srcA.server = server_start(&test->srcA, "src", &idA);
> > > > > > > + test->srcB.server = server_start(&test->srcB, "src", &idB);
> > > > > > > + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> > > > > > > + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> > > > > > > + test->dbus_loop = loop;
> > > > > > > + g_cond_signal(&cond);
> > > > > > > + g_mutex_unlock(&mutex);
> > > > > > > +
> > > > > > > + g_main_loop_run(loop);
> > > > > > > +
> > > > > > > + g_main_loop_unref(loop);
> > > > > > > + g_main_context_unref(context);
> > > > > > > +
> > > > > > > + g_mutex_lock(&mutex);
> > > > > > > + g_clear_object(&test->srcA.server);
> > > > > > > + g_clear_object(&test->srcB.server);
> > > > > > > + g_clear_object(&test->dstA.server);
> > > > > > > + g_clear_object(&test->dstB.server);
> > > > > > > + g_mutex_unlock(&mutex);
> > > > > > > +
> > > > > > > + return NULL;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static gboolean
> > > > > > > +wait_for_migration_complete(gpointer user_data)
> > > > > > > +{
> > > > > > > + Test *test = user_data;
> > > > > > > + QDict *rsp_return;
> > > > > > > + bool stop = false;
> > > > > > > + const char *status;
> > > > > > > +
> > > > > > > + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> > > > > > > + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> > > > > > > + status = qdict_get_str(rsp_return, "status");
> > > > > > > + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> > > > > > > + stop = true;
> > > > > > > + g_assert_cmpstr(status, ==,
> > > > > > > + test->migrate_fail ? "failed" : "completed");
> > > > > > > + }
> > > > > > > + qobject_unref(rsp_return);
> > > > > > > +
> > > > > > > + if (stop) {
> > > > > > > + g_main_loop_quit(test->loop);
> > > > > > > + }
> > > > > > > + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void migrate(QTestState *who, const char *uri)
> > > > > > > +{
> > > > > > > + QDict *args, *rsp;
> > > > > > > +
> > > > > > > + args = qdict_new();
> > > > > > > + qdict_put_str(args, "uri", uri);
> > > > > > > +
> > > > > > > + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> > > > > > > +
> > > > > > > + g_assert(qdict_haskey(rsp, "return"));
> > > > > > > + qobject_unref(rsp);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +test_dbus_vmstate(Test *test)
> > > > > > > +{
> > > > > > > + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> > > > > > > + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> > > > > > > + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> > > > > > > + GThread *t = g_thread_new("dbus", dbus_thread, test);
> > > > > > > +
> > > > > > > + g_mutex_lock(&mutex);
> > > > > > > + while (!test->dbus_loop) {
> > > > > > > + g_cond_wait(&cond, &mutex);
> > > > > > > + }
> > > > > > > +
> > > > > > > + src_qemu_args =
> > > > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > > > + "-object dbus-vmstate,id=dvB,addr=%s",
> > > > > > > + g_dbus_server_get_client_address(test->srcA.server),
> > > > > > > + g_dbus_server_get_client_address(test->srcB.server));
> > > > > > > +
> > > > > > > +
> > > > > > > + dst_qemu_args =
> > > > > > > + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> > > > > > > + "-object dbus-vmstate,id=dvB,addr=%s "
> > > > > > > + "-incoming %s",
> > > > > > > + g_dbus_server_get_client_address(test->dstA.server),
> > > > > > > + g_dbus_server_get_client_address(test->dstB.server),
> > > > > > > + uri);
> > > > > > > +
> > > > > > > + src_qemu = qtest_init(src_qemu_args);
> > > > > > > + dst_qemu = qtest_init(dst_qemu_args);
> > > > > > > +
> > > > > > > + test->loop = g_main_loop_new(NULL, TRUE);
> > > > > > > +
> > > > > > > + migrate(src_qemu, uri);
> > > > > > > + test->src_qemu = src_qemu;
> > > > > > > + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> > > > > > > +
> > > > > > > + g_main_loop_run(test->loop);
> > > > > > > + g_main_loop_unref(test->loop);
> > > > > > > +
> > > > > > > + g_free(uri);
> > > > > > > + qtest_quit(dst_qemu);
> > > > > > > + qtest_quit(src_qemu);
> > > > > > > + g_free(dst_qemu_args);
> > > > > > > + g_free(src_qemu_args);
> > > > > > > +
> > > > > > > + g_main_loop_quit(test->dbus_loop);
> > > > > > > + g_mutex_unlock(&mutex);
> > > > > > > +
> > > > > > > + g_thread_join(t);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +check_migrated(TestServer *s, TestServer *d)
> > > > > > > +{
> > > > > > > + assert(s->save_called);
> > > > > > > + assert(!s->load_called);
> > > > > > > + assert(!d->save_called);
> > > > > > > + assert(d->load_called);
> > > > > > > +}
> > > > > > > +
> > > > > > > +static void
> > > > > > > +test_dbus_vmstate_migrate(void)
> > > > > > > +{
> > > > > > > + Test test = { };
> > > > > > > +
> > > > > > > + test_dbus_vmstate(&test);
> > > > > > > +
> > > > > > > + check_migrated(&test.srcA, &test.dstA);
> > > > > > > + check_migrated(&test.srcB, &test.dstB);
> > > > > > > +}
> > > > > > > +
> > > > > > > +int
> > > > > > > +main(int argc, char **argv)
> > > > > > > +{
> > > > > > > + GError *err = NULL;
> > > > > > > + int ret;
> > > > > > > +
> > > > > > > + g_test_init(&argc, &argv, NULL);
> > > > > > > +
> > > > > > > + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> > > > > > > + if (!workdir) {
> > > > > > > + g_error("Unable to create temporary dir: %s\n", err->message);
> > > > > > > + }
> > > > > > > +
> > > > > > > + qtest_add_func("/dbus-vmstate/migrate",
> > > > > > > + test_dbus_vmstate_migrate);
> > > > > > > +
> > > > > > > + ret = g_test_run();
> > > > > > > +
> > > > > > > + rmdir(workdir);
> > > > > > > + g_free(workdir);
> > > > > > > +
> > > > > > > + return ret;
> > > > > > > +}
> > > > > > > diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> > > > > > > new file mode 100644
> > > > > > > index 0000000000..cc8563be4c
> > > > > > > --- /dev/null
> > > > > > > +++ b/tests/dbus-vmstate1.xml
> > > > > > > @@ -0,0 +1,12 @@
> > > > > > > +<?xml version="1.0"?>
> > > > > > > +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> > > > > > > + <interface name="org.qemu.VMState1">
> > > > > > > + <property name="Id" type="s" access="read"/>
> > > > > > > + <method name="Load">
> > > > > > > + <arg type="ay" name="data" direction="in"/>
> > > > > > > + </method>
> > > > > > > + <method name="Save">
> > > > > > > + <arg type="ay" name="data" direction="out"/>
> > > > > > > + </method>
> > > > > > > + </interface>
> > > > > > > +</node>
> > > > > > > --
> > > > > > > 2.23.0.rc1
> > > > > > >
> > > > > > --
> > > > > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > > > --
> > > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> >
>
>
> --
> Marc-André Lureau
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Hi
On Thu, Aug 8, 2019 at 7:03 PM Marc-André Lureau
<marcandre.lureau@redhat.com> wrote:
>
> When instanciated, this object will connect to the given D-Bus
> bus. During migration, it will take the data from org.qemu.VMState1
> instances.
I forgot to update the commit message.
When instantiated, this object will connect to the given D-Bus peer.
During migration, it will load/save the data from the
org.qemu.VMState1 interface.
See documentation for further details.
>
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> MAINTAINERS | 6 +
> backends/Makefile.objs | 4 +
> backends/dbus-vmstate.c | 332 ++++++++++++++++++++++++++++++
> configure | 7 +
> docs/interop/dbus-vmstate.rst | 63 ++++++
> docs/interop/index.rst | 1 +
> tests/Makefile.include | 18 +-
> tests/dbus-vmstate-test.c | 371 ++++++++++++++++++++++++++++++++++
> tests/dbus-vmstate1.xml | 12 ++
> 9 files changed, 813 insertions(+), 1 deletion(-)
> create mode 100644 backends/dbus-vmstate.c
> create mode 100644 docs/interop/dbus-vmstate.rst
> create mode 100644 tests/dbus-vmstate-test.c
> create mode 100644 tests/dbus-vmstate1.xml
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d6de200453..d136bf4f4b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2143,6 +2143,12 @@ F: tests/migration-test.c
> F: docs/devel/migration.rst
> F: qapi/migration.json
>
> +DBus VMState
> +M: Marc-André Lureau <marcandre.lureau@redhat.com>
> +S: Maintained
> +F: backends/dbus-vmstate.c
> +F: tests/dbus-vmstate*
> +
> Seccomp
> M: Eduardo Otubo <otubo@redhat.com>
> S: Supported
> diff --git a/backends/Makefile.objs b/backends/Makefile.objs
> index 981e8e122f..dbbe12b225 100644
> --- a/backends/Makefile.objs
> +++ b/backends/Makefile.objs
> @@ -17,3 +17,7 @@ endif
> common-obj-$(call land,$(CONFIG_VHOST_USER),$(CONFIG_VIRTIO)) += vhost-user.o
>
> common-obj-$(CONFIG_LINUX) += hostmem-memfd.o
> +
> +common-obj-$(CONFIG_GIO) += dbus-vmstate.o
> +dbus-vmstate.o-cflags = $(GIO_CFLAGS)
> +dbus-vmstate.o-libs = $(GIO_LIBS)
> diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c
> new file mode 100644
> index 0000000000..a9d9cac388
> --- /dev/null
> +++ b/backends/dbus-vmstate.c
> @@ -0,0 +1,332 @@
> +/*
> + * QEMU dbus-vmstate
> + *
> + * Copyright (C) 2019 Red Hat Inc
> + *
> + * Authors:
> + * Marc-André Lureau <marcandre.lureau@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 "qemu/error-report.h"
> +#include "qapi/error.h"
> +#include "qom/object_interfaces.h"
> +#include "qapi/qmp/qerror.h"
> +#include "migration/register.h"
> +#include "migration/qemu-file-types.h"
> +#include <gio/gio.h>
> +
> +typedef struct DBusVMState DBusVMState;
> +typedef struct DBusVMStateClass DBusVMStateClass;
> +
> +#define TYPE_DBUS_VMSTATE "dbus-vmstate"
> +#define DBUS_VMSTATE(obj) \
> + OBJECT_CHECK(DBusVMState, (obj), TYPE_DBUS_VMSTATE)
> +#define DBUS_VMSTATE_GET_CLASS(obj) \
> + OBJECT_GET_CLASS(DBusVMStateClass, (obj), TYPE_DBUS_VMSTATE)
> +#define DBUS_VMSTATE_CLASS(klass) \
> + OBJECT_CLASS_CHECK(DBusVMStateClass, (klass), TYPE_DBUS_VMSTATE)
> +
> +struct DBusVMStateClass {
> + ObjectClass parent_class;
> +};
> +
> +struct DBusVMState {
> + Object parent;
> +
> + GDBusConnection *bus;
> + GDBusProxy *proxy;
> + char *id;
> + char *dbus_addr;
> +};
> +
> +static const GDBusPropertyInfo vmstate_property_info[] = {
> + { -1, (char *) "Id", (char *) "s",
> + G_DBUS_PROPERTY_INFO_FLAGS_READABLE, NULL },
> +};
> +
> +static const GDBusPropertyInfo * const vmstate_property_info_pointers[] = {
> + &vmstate_property_info[0],
> + NULL
> +};
> +
> +static const GDBusInterfaceInfo vmstate1_interface_info = {
> + -1,
> + (char *) "org.qemu.VMState1",
> + (GDBusMethodInfo **) NULL,
> + (GDBusSignalInfo **) NULL,
> + (GDBusPropertyInfo **) &vmstate_property_info_pointers,
> + NULL,
> +};
> +
> +#define DBUS_VMSTATE_SIZE_LIMIT (1 << 20) /* 1mb */
> +
> +
> +static char *
> +get_idstr(DBusVMState *self)
> +{
> + return g_strdup_printf("%s-%s", TYPE_DBUS_VMSTATE, self->id);
> +}
> +
> +static char *
> +dbus_proxy_get_id(GDBusProxy *proxy, GError **err)
> +{
> + char *id = NULL;
> + GVariant *result = NULL;
> + size_t size;
> +
> + result = g_dbus_proxy_get_cached_property(proxy, "Id");
> + if (!result) {
> + g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
> + "Failed to get Id property");
> + return NULL;
> + }
> +
> + id = g_variant_dup_string(result, &size);
> + g_clear_pointer(&result, g_variant_unref);
> +
> + if (size == 0 || size >= 256) {
> + g_set_error_literal(err, G_IO_ERROR, G_IO_ERROR_FAILED,
> + "Invalid Id property");
> + g_free(id);
> + return NULL;
> + }
> +
> + return id;
> +}
> +
> +static int
> +dbus_load_state_proxy(GDBusProxy *proxy, const uint8_t *data, size_t size)
> +{
> + GError *err = NULL;
> + GVariant *value, *result;
> + int ret = -1;
> +
> + value = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> + data, size, sizeof(char));
> + result = g_dbus_proxy_call_sync(proxy, "Load",
> + g_variant_new("(@ay)", value),
> + G_DBUS_CALL_FLAGS_NO_AUTO_START,
> + -1, NULL, &err);
> + if (!result) {
> + error_report("Failed to Load: %s", err->message);
> + goto end;
> + }
> +
> + ret = 0;
> +
> +end:
> + g_clear_pointer(&result, g_variant_unref);
> + g_clear_error(&err);
> + return ret;
> +}
> +
> +static int
> +dbus_load_state(QEMUFile *f, void *opaque, int version_id)
> +{
> + DBusVMState *self = DBUS_VMSTATE(opaque);
> + uint8_t *data = NULL;
> + int ret = -1;
> + char id[256];
> + unsigned int size;
> +
> + if (qemu_get_counted_string(f, id) == 0) {
> + error_report("Invalid vmstate Id");
> + goto end;
> + }
> +
> + if (g_strcmp0(id, self->id)) {
> + error_report("Invalid vmstate Id: %s != %s", id, self->id);
> + goto end;
> + }
> +
> + size = qemu_get_be32(f);
> + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> + error_report("Invalid vmstate size: %u", size);
> + goto end;
> + }
> +
> + data = g_malloc(size);
> + if (qemu_get_buffer(f, data, size) != size) {
> + error_report("Failed to read %u bytes", size);
> + goto end;
> + }
> +
> + if (dbus_load_state_proxy(self->proxy, data, size) < 0) {
> + error_report("Failed to restore Id '%s'", id);
> + goto end;
> + }
> +
> + ret = 0;
> +
> +end:
> + g_clear_pointer(&data, g_free);
> + return ret;
> +}
> +
> +static void
> +dbus_save_state(QEMUFile *f, void *opaque)
> +{
> + DBusVMState *self = DBUS_VMSTATE(opaque);
> + GVariant *result = NULL, *child = NULL;
> + const uint8_t *data;
> + size_t size;
> + GError *err = NULL;
> +
> + result = g_dbus_proxy_call_sync(self->proxy, "Save",
> + NULL, G_DBUS_CALL_FLAGS_NO_AUTO_START,
> + -1, NULL, &err);
> + if (!result) {
> + error_report("Failed to Save: %s", err->message);
> + g_clear_error(&err);
> + goto end;
> + }
> +
> + child = g_variant_get_child_value(result, 0);
> + data = g_variant_get_fixed_array(child, &size, sizeof(char));
> + if (!data) {
> + error_report("Failed to Save: not a byte array");
> + goto end;
> + }
> + if (size > DBUS_VMSTATE_SIZE_LIMIT) {
> + error_report("Too much vmstate data to save: %zu", size);
> + goto end;
> + }
> +
> + qemu_put_counted_string(f, self->id);
> + qemu_put_be32(f, size);
> + qemu_put_buffer(f, data, size);
> +
> +end:
> + g_clear_pointer(&child, g_variant_unref);
> + g_clear_pointer(&result, g_variant_unref);
> +}
> +
> +static const SaveVMHandlers savevm_handlers = {
> + .save_state = dbus_save_state,
> + .load_state = dbus_load_state,
> +};
> +
> +static void
> +dbus_vmstate_complete(UserCreatable *uc, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(uc);
> + GError *err = NULL;
> + GDBusConnection *bus = NULL;
> + GDBusProxy *proxy = NULL;
> + char *idstr = NULL;
> +
> + if (!self->dbus_addr) {
> + error_setg(errp, QERR_MISSING_PARAMETER, "addr");
> + return;
> + }
> +
> + bus = g_dbus_connection_new_for_address_sync(self->dbus_addr,
> + G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT,
> + NULL, NULL, &err);
> + if (err) {
> + error_setg(errp, "failed to connect to DBus: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + self->bus = bus;
> +
> + proxy = g_dbus_proxy_new_sync(bus,
> + G_DBUS_PROXY_FLAGS_NONE,
> + (GDBusInterfaceInfo *) &vmstate1_interface_info,
> + NULL,
> + "/org/qemu/VMState1",
> + "org.qemu.VMState1",
> + NULL, &err);
> +
> + if (err) {
> + error_setg(errp, "failed to create DBus proxy: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + self->proxy = proxy;
> +
> + self->id = dbus_proxy_get_id(proxy, &err);
> + if (!self->id) {
> + error_setg(errp, "failed to get DBus Id: '%s'", err->message);
> + g_clear_error(&err);
> + return;
> + }
> +
> + idstr = get_idstr(self);
> + if (register_savevm_live(NULL, idstr, 0, 0,
> + &savevm_handlers, self) < 0) {
> + error_setg(errp, "Failed to register savevm handler");
> + }
> + g_free(idstr);
> +}
> +
> +static void
> +dbus_vmstate_finalize(Object *o)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> + char *idstr = get_idstr(self);
> +
> + unregister_savevm(NULL, idstr, self);
> +
> + g_clear_object(&self->bus);
> + g_clear_object(&self->proxy);
> + g_free(self->dbus_addr);
> + g_free(self->id);
> + g_free(idstr);
> +}
> +
> +static char *
> +get_dbus_addr(Object *o, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> +
> + return g_strdup(self->dbus_addr);
> +}
> +
> +static void
> +set_dbus_addr(Object *o, const char *str, Error **errp)
> +{
> + DBusVMState *self = DBUS_VMSTATE(o);
> +
> + g_free(self->dbus_addr);
> + self->dbus_addr = g_strdup(str);
> +}
> +
> +static void
> +dbus_vmstate_class_init(ObjectClass *oc, void *data)
> +{
> + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
> +
> + ucc->complete = dbus_vmstate_complete;
> +
> + object_class_property_add_str(oc, "addr",
> + get_dbus_addr, set_dbus_addr,
> + &error_abort);
> +}
> +
> +static const TypeInfo dbus_vmstate_info = {
> + .name = TYPE_DBUS_VMSTATE,
> + .parent = TYPE_OBJECT,
> + .instance_size = sizeof(DBusVMState),
> + .instance_finalize = dbus_vmstate_finalize,
> + .class_size = sizeof(DBusVMStateClass),
> + .class_init = dbus_vmstate_class_init,
> + .interfaces = (InterfaceInfo[]) {
> + { TYPE_USER_CREATABLE },
> + { }
> + }
> +};
> +
> +static void
> +register_types(void)
> +{
> + type_register_static(&dbus_vmstate_info);
> +}
> +
> +type_init(register_types);
> diff --git a/configure b/configure
> index 714e7fb6a1..e5b34f5ca7 100755
> --- a/configure
> +++ b/configure
> @@ -3665,10 +3665,16 @@ if $pkg_config --atleast-version=$glib_req_ver gio-2.0; then
> gio=yes
> gio_cflags=$($pkg_config --cflags gio-2.0)
> gio_libs=$($pkg_config --libs gio-2.0)
> + gdbus_codegen=$($pkg_config --variable=gdbus_codegen gio-2.0)
> else
> gio=no
> fi
>
> +if $pkg_config --atleast-version=$glib_req_ver gio-unix-2.0; then
> + gio_cflags="$gio_cflags $($pkg_config --cflags gio-unix-2.0)"
> + gio_libs="$gio_libs $($pkg_config --libs gio-unix-2.0)"
> +fi
> +
> # Sanity check that the current size_t matches the
> # size that glib thinks it should be. This catches
> # problems on multi-arch where people try to build
> @@ -6830,6 +6836,7 @@ if test "$gio" = "yes" ; then
> echo "CONFIG_GIO=y" >> $config_host_mak
> echo "GIO_CFLAGS=$gio_cflags" >> $config_host_mak
> echo "GIO_LIBS=$gio_libs" >> $config_host_mak
> + echo "GDBUS_CODEGEN=$gdbus_codegen" >> $config_host_mak
> fi
> echo "CONFIG_TLS_PRIORITY=\"$tls_priority\"" >> $config_host_mak
> if test "$gnutls" = "yes" ; then
> diff --git a/docs/interop/dbus-vmstate.rst b/docs/interop/dbus-vmstate.rst
> new file mode 100644
> index 0000000000..4a32a183fb
> --- /dev/null
> +++ b/docs/interop/dbus-vmstate.rst
> @@ -0,0 +1,63 @@
> +============
> +DBus VMState
> +============
> +
> +Introduction
> +============
> +
> +Helper processes may have their state migrated with the help of
> +QEMU "dbus-vmstate" objects.
> +
> +At this point, the connection to the helper is done in DBus
> +peer-to-peer mode (no initial Hello, and no bus name for
> +communication). The helper must be listening to the given address.
> +
> +Helper may save arbitrary data to be transferred in the migration
> +stream and restored/loaded on destination.
> +
> +The data amount to be transferred is limited to 1Mb. The state must be
> +saved quickly (a few seconds maximum). (DBus imposes a time limit on
> +reply anyway, and migration would fail if the data isn't given quickly
> +enough)
> +
> +Interface
> +=========
> +
> +On /org/qemu/VMState1 object path:
> +
> +.. code:: xml
> +
> + <interface name="org.qemu.VMState1">
> + <property name="Id" type="s" access="read"/>
> + <method name="Load">
> + <arg type="ay" name="data" direction="in"/>
> + </method>
> + <method name="Save">
> + <arg type="ay" name="data" direction="out"/>
> + </method>
> + </interface>
> +
> +"Id" property
> +-------------
> +
> +A utf8 encoded string that identifies the helper uniquely.
> +Must be <256 bytes.
> +
> +Load(in u8[] bytes) method
> +--------------------------
> +
> +The method called on destination with the state to restore.
> +
> +The helper may be initially started in a waiting state (with
> +an --incoming argument for example), and it may resume on load
> +success.
> +
> +An error may be returned to the caller.
> +
> +Save(out u8[] bytes) method
> +---------------------------
> +
> +The method called on the source to get the current state to be
> +migrated. The helper should continue to run normally.
> +
> +An error may be returned to the caller.
> diff --git a/docs/interop/index.rst b/docs/interop/index.rst
> index b4bfcab417..6bb173cfa6 100644
> --- a/docs/interop/index.rst
> +++ b/docs/interop/index.rst
> @@ -13,6 +13,7 @@ Contents:
> :maxdepth: 2
>
> bitmaps
> + dbus-vmstate
> live-block-operations
> pr-helper
> vhost-user
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index fd7fdb8658..2c610086a7 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -157,7 +157,9 @@ check-qtest-pci-$(CONFIG_RTL8139_PCI) += tests/rtl8139-test$(EXESUF)
> check-qtest-pci-$(CONFIG_VGA) += tests/display-vga-test$(EXESUF)
> check-qtest-pci-$(CONFIG_HDA) += tests/intel-hda-test$(EXESUF)
> check-qtest-pci-$(CONFIG_IVSHMEM_DEVICE) += tests/ivshmem-test$(EXESUF)
> -
> +ifneq ($(GDBUS_CODEGEN),)
> +check-qtest-pci-$(CONFIG_GIO) += tests/dbus-vmstate-test$(EXESUF)
> +endif
> check-qtest-i386-$(CONFIG_ISA_TESTDEV) = tests/endianness-test$(EXESUF)
> check-qtest-i386-y += tests/fdc-test$(EXESUF)
> check-qtest-i386-y += tests/ide-test$(EXESUF)
> @@ -618,6 +620,18 @@ tests/qapi-schema/doc-good.test.texi: $(SRC_PATH)/tests/qapi-schema/doc-good.jso
> @mv tests/qapi-schema/doc-good-qapi-doc.texi $@
> @rm -f tests/qapi-schema/doc-good-qapi-*.[ch] tests/qapi-schema/doc-good-qmp-*.[ch]
>
> +tests/dbus-vmstate1.h tests/dbus-vmstate1.c: tests/dbus-vmstate1-gen-timestamp ;
> +tests/dbus-vmstate1-gen-timestamp: $(SRC_PATH)/tests/dbus-vmstate1.xml
> + $(call quiet-command,$(GDBUS_CODEGEN) $< \
> + --interface-prefix org.qemu --generate-c-code tests/dbus-vmstate1, \
> + "GEN","$(@:%-timestamp=%)")
> + @>$@
> +
> +tests/dbus-vmstate1.o-cflags := $(GIO_CFLAGS)
> +tests/dbus-vmstate1.o-libs := $(GIO_LIBS)
> +
> +tests/dbus-vmstate-test.o: tests/dbus-vmstate1.h
> +
> tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
> tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)
> tests/test-qmp-event$(EXESUF): tests/test-qmp-event.o $(test-qapi-obj-y) tests/test-qapi-events.o
> @@ -820,6 +834,7 @@ tests/test-filter-mirror$(EXESUF): tests/test-filter-mirror.o $(qtest-obj-y)
> tests/test-filter-redirector$(EXESUF): tests/test-filter-redirector.o $(qtest-obj-y)
> tests/test-x86-cpuid-compat$(EXESUF): tests/test-x86-cpuid-compat.o $(qtest-obj-y)
> tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem-server.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> +tests/dbus-vmstate-test$(EXESUF): tests/dbus-vmstate-test.o tests/dbus-vmstate1.o $(libqos-pc-obj-y) $(libqos-spapr-obj-y)
> tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o $(test-util-obj-y) libvhost-user.a
> tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
> tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> @@ -1172,6 +1187,7 @@ check-clean:
> rm -rf $(check-unit-y) tests/*.o $(QEMU_IOTESTS_HELPERS-y)
> rm -rf $(sort $(foreach target,$(SYSEMU_TARGET_LIST), $(check-qtest-$(target)-y)) $(check-qtest-generic-y))
> rm -f tests/test-qapi-gen-timestamp
> + rm -f tests/dbus-vmstate1-gen-timestamp
> rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
>
> clean: check-clean
> diff --git a/tests/dbus-vmstate-test.c b/tests/dbus-vmstate-test.c
> new file mode 100644
> index 0000000000..45d44916d2
> --- /dev/null
> +++ b/tests/dbus-vmstate-test.c
> @@ -0,0 +1,371 @@
> +#include "qemu/osdep.h"
> +#include <glib/gstdio.h>
> +#include <gio/gio.h>
> +#include "libqtest.h"
> +#include "qemu-common.h"
> +#include "dbus-vmstate1.h"
> +
> +static char *workdir;
> +
> +typedef struct TestServerId {
> + const char *name;
> + const char *data;
> + size_t size;
> +} TestServerId;
> +
> +static const TestServerId idA = {
> + "idA", "I'am\0idA!", sizeof("I'am\0idA!")
> +};
> +
> +static const TestServerId idB = {
> + "idB", "I'am\0idB!", sizeof("I'am\0idB!")
> +};
> +
> +typedef struct TestServer {
> + const TestServerId *id;
> + bool save_called;
> + bool load_called;
> + GDBusObjectManagerServer *om;
> + GDBusServer *server;
> +} TestServer;
> +
> +typedef struct Test {
> + bool migrate_fail;
> + TestServer srcA;
> + TestServer dstA;
> + TestServer srcB;
> + TestServer dstB;
> + GMainLoop *loop, *dbus_loop;
> + QTestState *src_qemu;
> +} Test;
> +
> +GMutex mutex;
> +GCond cond;
> +
> +static gboolean
> +vmstate_load(VMState1 *object, GDBusMethodInvocation *invocation,
> + const gchar *arg_data, gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GVariant *args, *var;
> + const uint8_t *data;
> + size_t size;
> +
> + args = g_dbus_method_invocation_get_parameters(invocation);
> + var = g_variant_get_child_value(args, 0);
> + data = g_variant_get_fixed_array(var, &size, sizeof(char));
> + g_assert_cmpuint(size, ==, h->id->size);
> + g_assert(!memcmp(data, h->id->data, h->id->size));
> + h->load_called = true;
> + g_variant_unref(var);
> +
> + g_dbus_method_invocation_return_value(invocation, g_variant_new("()"));
> + return TRUE;
> +}
> +
> +static gboolean
> +vmstate_save(VMState1 *object, GDBusMethodInvocation *invocation,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GVariant *var;
> +
> + var = g_variant_new_fixed_array(G_VARIANT_TYPE_BYTE,
> + h->id->data, h->id->size, sizeof(char));
> + g_dbus_method_invocation_return_value(invocation,
> + g_variant_new("(@ay)", var));
> + h->save_called = true;
> +
> + return TRUE;
> +}
> +
> +static void
> +connection_closed(GDBusConnection *connection,
> + gboolean remote_peer_vanished,
> + GError *Error,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> +
> + g_clear_object(&h->om);
> + g_clear_object(&connection);
> +}
> +
> +static GDBusObjectManagerServer *
> +get_omserver(GDBusConnection *conn, gpointer user_data)
> +{
> + TestServer *h = user_data;
> + GDBusObjectManagerServer *om;
> + GDBusObjectSkeleton *sk;
> + VMState1 *v;
> +
> + om = g_dbus_object_manager_server_new("/org/qemu");
> + sk = g_dbus_object_skeleton_new("/org/qemu/VMState1");
> +
> + v = vmstate1_skeleton_new();
> + g_object_set(v, "id", h->id->name, NULL);
> + g_signal_connect(v, "handle-load", G_CALLBACK(vmstate_load), user_data);
> + g_signal_connect(v, "handle-save", G_CALLBACK(vmstate_save), user_data);
> +
> + g_dbus_object_skeleton_add_interface(sk, G_DBUS_INTERFACE_SKELETON(v));
> + g_dbus_object_manager_server_export(om, sk);
> + g_dbus_object_manager_server_set_connection(om, conn);
> +
> + g_clear_object(&v);
> + g_clear_object(&sk);
> +
> + return om;
> +}
> +
> +static gboolean
> +on_new_connection(GDBusServer *server,
> + GDBusConnection *connection,
> + gpointer user_data)
> +{
> + TestServer *h = user_data;
> +
> + g_object_ref(connection);
> + g_signal_connect(connection, "closed",
> + G_CALLBACK(connection_closed), user_data);
> + h->om = get_omserver(connection, user_data);
> +
> + return TRUE;
> +}
> +
> +static gboolean
> +allow_mechanism_cb(GDBusAuthObserver *observer,
> + const gchar *mechanism,
> + gpointer user_data)
> +{
> + return g_strcmp0(mechanism, "EXTERNAL") == 0;
> +}
> +
> +static gboolean
> +authorize_authenticated_peer_cb(GDBusAuthObserver *observer,
> + GIOStream *stream,
> + GCredentials *credentials,
> + gpointer user_data)
> +{
> + gboolean authorized = FALSE;
> +
> + if (credentials != NULL) {
> + GCredentials *own_credentials = g_credentials_new();
> +
> + if (g_credentials_is_same_user(credentials, own_credentials, NULL)) {
> + authorized = TRUE;
> + }
> +
> + g_clear_object(&own_credentials);
> + }
> +
> + return authorized;
> +}
> +
> +static GDBusServer *
> +server_start(TestServer *h, const char *p, const TestServerId *id)
> +{
> + GDBusAuthObserver *observer = NULL;
> + GDBusServer *server = NULL;
> + gchar *guid = NULL;
> + GError *error = NULL;
> + char *addr = NULL;
> +
> + h->id = id;
> + addr = g_strdup_printf("unix:path=%s/dbus-%s%s", workdir, p, h->id->name);
> + guid = g_dbus_generate_guid();
> + observer = g_dbus_auth_observer_new();
> + g_signal_connect(observer, "allow-mechanism",
> + G_CALLBACK(allow_mechanism_cb), h);
> + g_signal_connect(observer, "authorize-authenticated-peer",
> + G_CALLBACK(authorize_authenticated_peer_cb), h);
> +
> + server = g_dbus_server_new_sync(addr,
> + G_DBUS_SERVER_FLAGS_NONE,
> + guid,
> + observer,
> + NULL, /* GCancellable */
> + &error);
> + g_dbus_server_start(server);
> + g_clear_object(&observer);
> + g_free(guid);
> +
> + if (server == NULL) {
> + g_printerr("Error creating server at address %s: %s\n",
> + addr, error->message);
> + g_error_free(error);
> + return NULL;
> + }
> +
> + g_signal_connect(server, "new-connection",
> + G_CALLBACK(on_new_connection), h);
> +
> + g_free(addr);
> + return server;
> +}
> +
> +
> +static gpointer
> +dbus_thread(gpointer p)
> +{
> + Test *test = p;
> + GMainContext *context = g_main_context_new();
> + GMainLoop *loop = g_main_loop_new(context, FALSE);
> +
> + g_main_context_push_thread_default(context);
> +
> + g_mutex_lock(&mutex);
> + test->srcA.server = server_start(&test->srcA, "src", &idA);
> + test->srcB.server = server_start(&test->srcB, "src", &idB);
> + test->dstA.server = server_start(&test->dstA, "dst", &idA);
> + test->dstB.server = server_start(&test->dstB, "dst", &idB);
> + test->dbus_loop = loop;
> + g_cond_signal(&cond);
> + g_mutex_unlock(&mutex);
> +
> + g_main_loop_run(loop);
> +
> + g_main_loop_unref(loop);
> + g_main_context_unref(context);
> +
> + g_mutex_lock(&mutex);
> + g_clear_object(&test->srcA.server);
> + g_clear_object(&test->srcB.server);
> + g_clear_object(&test->dstA.server);
> + g_clear_object(&test->dstB.server);
> + g_mutex_unlock(&mutex);
> +
> + return NULL;
> +}
> +
> +static gboolean
> +wait_for_migration_complete(gpointer user_data)
> +{
> + Test *test = user_data;
> + QDict *rsp_return;
> + bool stop = false;
> + const char *status;
> +
> + qtest_qmp_send(test->src_qemu, "{ 'execute': 'query-migrate' }");
> + rsp_return = qtest_qmp_receive_success(test->src_qemu, NULL, NULL);
> + status = qdict_get_str(rsp_return, "status");
> + if (g_str_equal(status, "completed") || g_str_equal(status, "failed")) {
> + stop = true;
> + g_assert_cmpstr(status, ==,
> + test->migrate_fail ? "failed" : "completed");
> + }
> + qobject_unref(rsp_return);
> +
> + if (stop) {
> + g_main_loop_quit(test->loop);
> + }
> + return stop ? G_SOURCE_REMOVE : G_SOURCE_CONTINUE;
> +}
> +
> +static void migrate(QTestState *who, const char *uri)
> +{
> + QDict *args, *rsp;
> +
> + args = qdict_new();
> + qdict_put_str(args, "uri", uri);
> +
> + rsp = qtest_qmp(who, "{ 'execute': 'migrate', 'arguments': %p }", args);
> +
> + g_assert(qdict_haskey(rsp, "return"));
> + qobject_unref(rsp);
> +}
> +
> +static void
> +test_dbus_vmstate(Test *test)
> +{
> + QTestState *src_qemu = NULL, *dst_qemu = NULL;
> + char *src_qemu_args = NULL, *dst_qemu_args = NULL;
> + char *uri = g_strdup_printf("unix:%s/migsocket", workdir);
> + GThread *t = g_thread_new("dbus", dbus_thread, test);
> +
> + g_mutex_lock(&mutex);
> + while (!test->dbus_loop) {
> + g_cond_wait(&cond, &mutex);
> + }
> +
> + src_qemu_args =
> + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> + "-object dbus-vmstate,id=dvB,addr=%s",
> + g_dbus_server_get_client_address(test->srcA.server),
> + g_dbus_server_get_client_address(test->srcB.server));
> +
> +
> + dst_qemu_args =
> + g_strdup_printf("-object dbus-vmstate,id=dvA,addr=%s "
> + "-object dbus-vmstate,id=dvB,addr=%s "
> + "-incoming %s",
> + g_dbus_server_get_client_address(test->dstA.server),
> + g_dbus_server_get_client_address(test->dstB.server),
> + uri);
> +
> + src_qemu = qtest_init(src_qemu_args);
> + dst_qemu = qtest_init(dst_qemu_args);
> +
> + test->loop = g_main_loop_new(NULL, TRUE);
> +
> + migrate(src_qemu, uri);
> + test->src_qemu = src_qemu;
> + g_timeout_add_seconds(1, wait_for_migration_complete, test);
> +
> + g_main_loop_run(test->loop);
> + g_main_loop_unref(test->loop);
> +
> + g_free(uri);
> + qtest_quit(dst_qemu);
> + qtest_quit(src_qemu);
> + g_free(dst_qemu_args);
> + g_free(src_qemu_args);
> +
> + g_main_loop_quit(test->dbus_loop);
> + g_mutex_unlock(&mutex);
> +
> + g_thread_join(t);
> +}
> +
> +static void
> +check_migrated(TestServer *s, TestServer *d)
> +{
> + assert(s->save_called);
> + assert(!s->load_called);
> + assert(!d->save_called);
> + assert(d->load_called);
> +}
> +
> +static void
> +test_dbus_vmstate_migrate(void)
> +{
> + Test test = { };
> +
> + test_dbus_vmstate(&test);
> +
> + check_migrated(&test.srcA, &test.dstA);
> + check_migrated(&test.srcB, &test.dstB);
> +}
> +
> +int
> +main(int argc, char **argv)
> +{
> + GError *err = NULL;
> + int ret;
> +
> + g_test_init(&argc, &argv, NULL);
> +
> + workdir = g_dir_make_tmp("dbus-vmstate-test-XXXXXX", &err);
> + if (!workdir) {
> + g_error("Unable to create temporary dir: %s\n", err->message);
> + }
> +
> + qtest_add_func("/dbus-vmstate/migrate",
> + test_dbus_vmstate_migrate);
> +
> + ret = g_test_run();
> +
> + rmdir(workdir);
> + g_free(workdir);
> +
> + return ret;
> +}
> diff --git a/tests/dbus-vmstate1.xml b/tests/dbus-vmstate1.xml
> new file mode 100644
> index 0000000000..cc8563be4c
> --- /dev/null
> +++ b/tests/dbus-vmstate1.xml
> @@ -0,0 +1,12 @@
> +<?xml version="1.0"?>
> +<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
> + <interface name="org.qemu.VMState1">
> + <property name="Id" type="s" access="read"/>
> + <method name="Load">
> + <arg type="ay" name="data" direction="in"/>
> + </method>
> + <method name="Save">
> + <arg type="ay" name="data" direction="out"/>
> + </method>
> + </interface>
> +</node>
> --
> 2.23.0.rc1
>
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