hw/virtio: Also include md stubs in case CONFIG_VIRTIO_PCI is not set

For the s390x target, it's possible to build the QEMU binary without
CONFIG_VIRTIO_PCI and only have the virtio-mem device via the ccw
transport. In that case, QEMU currently fails to link correctly:

 /usr/bin/ld: libqemu-s390x-softmmu.a.p/hw_s390x_s390-virtio-ccw.c.o: in function `s390_machine_device_pre_plug':
 ../hw/s390x/s390-virtio-ccw.c:579:(.text+0x1e96): undefined reference to `virtio_md_pci_pre_plug'
 /usr/bin/ld: libqemu-s390x-softmmu.a.p/hw_s390x_s390-virtio-ccw.c.o: in function `s390_machine_device_plug':
 ../hw/s390x/s390-virtio-ccw.c:608:(.text+0x21a4): undefined reference to `virtio_md_pci_plug'
 /usr/bin/ld: libqemu-s390x-softmmu.a.p/hw_s390x_s390-virtio-ccw.c.o: in function `s390_machine_device_unplug_request':
 ../hw/s390x/s390-virtio-ccw.c:622:(.text+0x2334): undefined reference to `virtio_md_pci_unplug_request'
 /usr/bin/ld: libqemu-s390x-softmmu.a.p/hw_s390x_s390-virtio-ccw.c.o: in function `s390_machine_device_unplug':
 ../hw/s390x/s390-virtio-ccw.c:633:(.text+0x2436): undefined reference to `virtio_md_pci_unplug'
 clang: error: linker command failed with exit code 1 (use -v to see invocation)

We also need to include the stubs when CONFIG_VIRTIO_PCI is missing.

Fixes: aa910c2 ("s390x: virtio-mem support")
Message-ID: <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Thomas Huth <[email protected]>

Author: huth

hw/virtio/meson.build

@@ -90,7 +90,8 @@ specific_virtio_ss.add_all(when: 'CONFIG_VIRTIO_PCI', if_true: virtio_pci_ss)
 system_ss.add_all(when: 'CONFIG_VIRTIO', if_true: system_virtio_ss)
 system_ss.add(when: 'CONFIG_VIRTIO', if_false: files('vhost-stub.c'))
 system_ss.add(when: 'CONFIG_VIRTIO', if_false: files('virtio-stub.c'))
-system_ss.add(when: 'CONFIG_VIRTIO_MD', if_false: files('virtio-md-stubs.c'))
+system_ss.add(when: ['CONFIG_VIRTIO_MD', 'CONFIG_VIRTIO_PCI'],
+              if_false: files('virtio-md-stubs.c'))
 
 system_ss.add(files('virtio-hmp-cmds.c'))