[PATCH] [v2] vfio-mdev: add back CONFIG_VFIO dependency

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

CONFIG_VFIO_MDEV cannot be selected when VFIO itself is
disabled, otherwise we get a link failure:

WARNING: unmet direct dependencies detected for VFIO_MDEV
  Depends on [n]: VFIO [=n]
  Selected by [y]:
  - SAMPLE_VFIO_MDEV_MTTY [=y] && SAMPLES [=y]
  - SAMPLE_VFIO_MDEV_MDPY [=y] && SAMPLES [=y]
  - SAMPLE_VFIO_MDEV_MBOCHS [=y] && SAMPLES [=y]
/home/arnd/cross/arm64/gcc-13.0.1-nolibc/x86_64-linux/bin/x86_64-linux-ld: samples/vfio-mdev/mdpy.o: in function `mdpy_remove':
mdpy.c:(.text+0x1e1): undefined reference to `vfio_unregister_group_dev'
/home/arnd/cross/arm64/gcc-13.0.1-nolibc/x86_64-linux/bin/x86_64-linux-ld: samples/vfio-mdev/mdpy.o: in function `mdpy_probe':
mdpy.c:(.text+0x149e): undefined reference to `_vfio_alloc_device'

Fixes: 8bf8c5ee1f38 ("vfio-mdev: turn VFIO_MDEV into a selectable symbol")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: fix the s390 and drm drivers as well, in addition to the
sample code.
---
 arch/s390/Kconfig            | 4 +++-
 drivers/gpu/drm/i915/Kconfig | 1 +
 samples/Kconfig              | 3 +++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 045e681caa36..078cd1a773a3 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -715,6 +715,7 @@ config VFIO_CCW
 	def_tristate n
 	prompt "Support for VFIO-CCW subchannels"
 	depends on S390_CCW_IOMMU
+	depends on VFIO
 	select VFIO_MDEV
 	help
 	  This driver allows usage of I/O subchannels via VFIO-CCW.
@@ -726,8 +727,9 @@ config VFIO_AP
 	def_tristate n
 	prompt "VFIO support for AP devices"
 	depends on S390_AP_IOMMU && KVM
-	select VFIO_MDEV
+	depends on VFIO
 	depends on ZCRYPT
+	select VFIO_MDEV
 	help
 	  This driver grants access to Adjunct Processor (AP) devices
 	  via the VFIO mediated device interface.
diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index a14f68730d6d..b84c16933bbd 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -120,6 +120,7 @@ config DRM_I915_GVT_KVMGT
 	depends on X86
 	depends on 64BIT
 	depends on KVM
+	depends on VFIO
 	select DRM_I915_GVT
 	select KVM_EXTERNAL_WRITE_TRACKING
 	select VFIO_MDEV
diff --git a/samples/Kconfig b/samples/Kconfig
index 56b191d128d8..44a09dfa8a0b 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -185,6 +185,7 @@ config SAMPLE_UHID
 
 config SAMPLE_VFIO_MDEV_MTTY
 	tristate "Build VFIO mtty example mediated device sample code"
+	depends on VFIO
 	select VFIO_MDEV
 	help
 	  Build a virtual tty sample driver for use as a VFIO
@@ -192,6 +193,7 @@ config SAMPLE_VFIO_MDEV_MTTY
 
 config SAMPLE_VFIO_MDEV_MDPY
 	tristate "Build VFIO mdpy example mediated device sample code"
+	depends on VFIO
 	select VFIO_MDEV
 	help
 	  Build a virtual display sample driver for use as a VFIO
@@ -209,6 +211,7 @@ config SAMPLE_VFIO_MDEV_MDPY_FB
 
 config SAMPLE_VFIO_MDEV_MBOCHS
 	tristate "Build VFIO mdpy example mediated device sample code"
+	depends on VFIO
 	select VFIO_MDEV
 	select DMA_SHARED_BUFFER
 	help
-- 
2.39.0