VirtIO config option

Make virtio devices optional.  Selecting individual devices is not useful
as the host bindings are all in one file.
Signed-off-by: NPaul Brook <paul@codesourcery.com>

Makefile.objs

@@ -42,6 +42,11 @@ net-nested-$(CONFIG_SLIRP) += slirp.o
 net-nested-$(CONFIG_VDE) += vde.o
 net-obj-y += $(addprefix net/, $(net-nested-y))
 
+ifeq ($(CONFIG_VIRTIO)$(CONFIG_VIRTFS),yy)
+# 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.
+CONFIG_REALLY_VIRTFS=y
+endif
 fsdev-nested-$(CONFIG_VIRTFS) = qemu-fsdev.o
 fsdev-obj-$(CONFIG_VIRTFS) += $(addprefix fsdev/, $(fsdev-nested-y))
 
@@ -159,7 +164,7 @@ user-obj-y += cutils.o cache-utils.o
 
 hw-obj-y =
 hw-obj-y += vl.o loader.o
-hw-obj-y += virtio.o virtio-console.o
+hw-obj-$(CONFIG_VIRTIO) += virtio.o virtio-console.o
 hw-obj-y += fw_cfg.o
 # FIXME: Core PCI code and its direct dependencies are required by the
 # QMP query-pci command.
@@ -264,7 +269,8 @@ sound-obj-$(CONFIG_HDA) += intel-hda.o hda-audio.o
 adlib.o fmopl.o: QEMU_CFLAGS += -DBUILD_Y8950=0
 hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
 
-hw-obj-$(CONFIG_VIRTFS) += virtio-9p-debug.o virtio-9p-local.o virtio-9p-xattr.o
+hw-obj-$(CONFIG_REALLY_VIRTFS) += virtio-9p-debug.o
+hw-obj-$(CONFIG_VIRTFS) += virtio-9p-local.o virtio-9p-xattr.o
 hw-obj-$(CONFIG_VIRTFS) += virtio-9p-xattr-user.o virtio-9p-posix-acl.o
 
 ######################################################################

Makefile.target

@@ -188,11 +188,11 @@ ifdef CONFIG_SOFTMMU
 obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o balloon.o
 # virtio has to be here due to weird dependency between PCI and virtio-net.
 # need to fix this properly
-obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o
+obj-$(CONFIG_VIRTIO) += virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 obj-y += vhost_net.o
 obj-$(CONFIG_VHOST_NET) += vhost.o
-obj-$(CONFIG_VIRTFS) += virtio-9p.o
+obj-$(CONFIG_REALLY_VIRTFS) += virtio-9p.o
 obj-y += rwhandler.o
 obj-$(CONFIG_KVM) += kvm.o kvm-all.o
 obj-$(CONFIG_NO_KVM) += kvm-stub.o

default-configs/s390x-softmmu.mak

+include virtio.mak