[PATCH-for-5.2 v3 2/4] hw/9pfs: Fix Kconfig dependency problem between 9pfs and Xen

[Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>]

Commit b2c00bce54c ("meson: convert hw/9pfs, cleanup") introduced
CONFIG_9PFS (probably a wrong conflict resolution). This config is
not used anywhere. Backends depend on CONFIG_FSDEV_9P which itself
depends on CONFIG_VIRTFS.

Remove the invalid CONFIG_9PFS and use CONFIG_FSDEV_9P instead, to
fix the './configure --without-default-devices --enable-xen' build:

  /usr/bin/ld: libcommon.fa.p/hw_xen_xen-legacy-backend.c.o: in function 
`xen_be_register_common':
  hw/xen/xen-legacy-backend.c:754: undefined reference to `xen_9pfs_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x8): undefined 
reference to `local_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x20): undefined 
reference to `synth_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x38): undefined 
reference to `proxy_ops'
  collect2: error: ld returned 1 exit status

Fixes: b2c00bce54c ("meson: convert hw/9pfs, cleanup")
Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Acked-by: Greg Kurz <groug@xxxxxxxx>
Tested-by: Greg Kurz <groug@xxxxxxxx>
Signed-off-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
---
v2: Reworded description (Greg)

Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Anthony Perard <anthony.perard@xxxxxxxxxx>
Cc: Paul Durrant <paul@xxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Cc: Greg Kurz <groug@xxxxxxxx>
Cc: Christian Schoenebeck <qemu_oss@xxxxxxxxxxxxx>
---
 hw/9pfs/Kconfig     | 4 ----
 hw/9pfs/meson.build | 2 +-
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/hw/9pfs/Kconfig b/hw/9pfs/Kconfig
index d3ebd737301..3ae57496613 100644
--- a/hw/9pfs/Kconfig
+++ b/hw/9pfs/Kconfig
@@ -2,12 +2,8 @@ config FSDEV_9P
     bool
     depends on VIRTFS
 
-config 9PFS
-    bool
-
 config VIRTIO_9P
     bool
     default y
     depends on VIRTFS && VIRTIO
     select FSDEV_9P
-    select 9PFS
diff --git a/hw/9pfs/meson.build b/hw/9pfs/meson.build
index cc094262122..99be5d91196 100644
--- a/hw/9pfs/meson.build
+++ b/hw/9pfs/meson.build
@@ -15,6 +15,6 @@
   'coxattr.c',
 ))
 fs_ss.add(when: 'CONFIG_XEN', if_true: files('xen-9p-backend.c'))
-softmmu_ss.add_all(when: 'CONFIG_9PFS', if_true: fs_ss)
+softmmu_ss.add_all(when: 'CONFIG_FSDEV_9P', if_true: fs_ss)
 
 specific_ss.add(when: 'CONFIG_VIRTIO_9P', if_true: files('virtio-9p-device.c'))
-- 
2.26.2