-ifeq ($(CONFIG_VIRTIO)$(CONFIG_VIRTFS)$(CONFIG_PCI),yyy)
# Lots of the fsdev/9pcode is pulled in by vl.c via qemu_fsdev_add.
-# only pull in the actual virtio-9p device if we also enabled virtio.
-common-obj-y = qemu-fsdev.o 9p-marshal.o 9p-iov-marshal.o
-else
-common-obj-y = qemu-fsdev-dummy.o
-endif
-common-obj-y += qemu-fsdev-opts.o
+# only pull in the actual 9p backend if we also enabled virtio or xen.
+common-obj-$(call land,$(CONFIG_VIRTFS),$(call lor,$(CONFIG_VIRTIO),$(CONFIG_XEN))) = qemu-fsdev.o 9p-marshal.o 9p-iov-marshal.o
+common-obj-$(call lnot,$(call land,$(CONFIG_VIRTFS),$(call lor,$(CONFIG_VIRTIO),$(CONFIG_XEN)))) = qemu-fsdev-dummy.o
+common-obj-y += qemu-fsdev-opts.o qemu-fsdev-throttle.o
# Toplevel always builds this; targets without virtio will put it in
# common-obj-y