s390x: express dependencies with Kconfig

Instead of hard-coding all config switches in the config file
default-configs/s390x-softmmu.mak, let's use the new Kconfig files
to express the necessary dependencies: The S390_CCW_VIRTIO config switch
for the "s390-ccw-virtio" machine now selects all non-optional devices.

And since we already have the VIRTIO_PCI and VIRTIO_MMIO config switches
for the other two virtio transports, this patch also introduces a new
config switch VIRTIO_CCW for the third, s390x-specific virtio transport,
so that all three virtio transports are now handled in the same way.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

default-configs/s390x-softmmu.mak

@@ -1,9 +1,13 @@
-CONFIG_PCI=y
-CONFIG_VIRTIO_PCI=y
-CONFIG_SCLPCONSOLE=y
-CONFIG_TERMINAL3270=y
-CONFIG_S390_FLIC=y
-CONFIG_WDT_DIAG288=y
+# Default configuration for s390x-softmmu
+
+# Uncomment the following lines to disable these optional devices:
+#
+#CONFIG_TERMINAL3270=n
+#CONFIG_VFIO_AP=n
+#CONFIG_VFIO_CCW=n
+#CONFIG_VIRTIO_PCI=n
+#CONFIG_WDT_DIAG288=n
+
+# Boards:
+#
 CONFIG_S390_CCW_VIRTIO=y
-CONFIG_VFIO_CCW=y
-CONFIG_VFIO_AP=y

hw/s390x/Kconfig

@@ -1,2 +1,11 @@
 config S390_CCW_VIRTIO
     bool
+    imply VIRTIO_PCI
+    imply TERMINAL3270
+    imply VFIO_AP
+    imply VFIO_CCW
+    imply WDT_DIAG288
+    select PCI
+    select S390_FLIC
+    select SCLPCONSOLE
+    select VIRTIO_CCW

hw/s390x/Makefile.objs

@@ -6,7 +6,8 @@ obj-y += sclpcpu.o
 obj-y += ipl.o
 obj-y += css.o
 obj-$(CONFIG_S390_CCW_VIRTIO) += s390-virtio-ccw.o
-obj-y += 3270-ccw.o
+obj-$(CONFIG_TERMINAL3270) += 3270-ccw.o
+ifeq ($(CONFIG_VIRTIO_CCW),y)
 obj-y += virtio-ccw.o
 obj-$(CONFIG_VIRTIO_SERIAL) += virtio-ccw-serial.o
 obj-$(CONFIG_VIRTIO_BALLOON) += virtio-ccw-balloon.o
@@ -19,6 +20,7 @@ obj-$(CONFIG_VIRTIO_NET) += virtio-ccw-net.o
 obj-$(CONFIG_VIRTIO_BLK) += virtio-ccw-blk.o
 obj-$(call land,$(CONFIG_VIRTIO_9P),$(CONFIG_VIRTFS)) += virtio-ccw-9p.o
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-ccw.o
+endif
 obj-y += css-bridge.o
 obj-y += ccw-device.o
 obj-y += s390-pci-bus.o s390-pci-inst.o

hw/virtio/Kconfig

@@ -16,6 +16,10 @@ config VIRTIO_MMIO
     bool
     select VIRTIO
 
+config VIRTIO_CCW
+    bool
+    select VIRTIO
+
 config VIRTIO_BALLOON
     bool
     default y