vfio: Depend on MMU

commit b2b12db upstream.

VFIO_IOMMU_TYPE1 does not compile with !MMU:

../drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
../drivers/vfio/vfio_iommu_type1.c:536:22: error: implicit declaration of function 'pte_write'; did you mean 'vfs_write'? [-Werror=implicit-function-declaration]

So require it.

Suggested-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: jgunthorpe

drivers/vfio/Kconfig

@@ -22,7 +22,7 @@ config VFIO_VIRQFD
 menuconfig VFIO
 	tristate "VFIO Non-Privileged userspace driver framework"
 	select IOMMU_API
-	select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM || ARM64)
+	select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
 	help
 	  VFIO provides a framework for secure userspace device drivers.
 	  See Documentation/driver-api/vfio.rst for more details.