commit 0ee3bfc2c31ec4aabd542aa6b7aa6609bf40c7a1
author Jason Gunthorpe <jgg@nvidia.com> Thu Mar 04 21:30:03 2021 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fri May 07 10:51:38 2021 +0200
tree 2e23a4bc0a617f7a0bf1d8f72a828ac01b0119f1
parent b246759284d6a2bc5b6f1009caeeb3abce2ec9ff

vfio: Depend on MMU

commit b2b12db53507bc97d96f6b7cb279e831e5eafb00 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 <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <0-v1-02cb5500df6e+78-vfio_no_mmu_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/vfio/Kconfig

diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 9dc9502..503ed2f 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -22,7 +22,7 @@
 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.