Add dbus-vmstate object

When instantiated, this object will connect to the given D-Bus bus
"addr". During migration, it will take/restore the data from
org.qemu.VMState1 instances. See documentation for details.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

MAINTAINERS

@@ -2209,9 +2209,11 @@ F: qapi/migration.json
 D-Bus
 M: Marc-André Lureau <marcandre.lureau@redhat.com>
 S: Maintained
+F: backends/dbus-vmstate.c
 F: util/dbus.c
 F: include/qemu/dbus.h
 F: docs/interop/dbus.rst
+F: docs/interop/dbus-vmstate.rst
 
 Seccomp
 M: Eduardo Otubo <otubo@redhat.com>

Makefile.objs

@@ -128,6 +128,7 @@ vhost-user-gpu-obj-y = contrib/vhost-user-gpu/
 trace-events-subdirs =
 trace-events-subdirs += accel/kvm
 trace-events-subdirs += accel/tcg
+trace-events-subdirs += backends
 trace-events-subdirs += crypto
 trace-events-subdirs += monitor
 ifeq ($(CONFIG_USER_ONLY),y)

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)