From: Jason Gunthorpe jgg@nvidia.com

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 Cc: stable@vger.kernel.org # 5.11.y, 5.10.y, 5.4.y Signed-off-by: Alex Williamson alex.williamson@redhat.com ---

The noted stable branches include upstream commit 179209fa1270 ("vfio: IOMMU_API should be selected") without the follow-up commit b2b12db53507 ("vfio: Depend on MMU"), which should have included a Fixes: tag for the prior commit. Without this latter commit, we're susceptible to randconfig failures with !MMU configs. Thanks!

drivers/vfio/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig index 90c0525b1e0c..67d0bf4efa16 100644 --- a/drivers/vfio/Kconfig +++ b/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.