Commit faa37ff3bf18 for kernel

commit faa37ff3bf18d5242fe3d54f5462b1c3254c2567
Author: Jason Gunthorpe <jgg@ziepe.ca>
Date:   Tue Jan 6 15:22:11 2026 -0400

    iommufd/selftest: Add missing kconfig for DMA_SHARED_BUFFER

    The test doesn't build without it, dma-buf.h does not provide stub
    functions if it is not enabled. Compilation can fail with:

     ERROR:root:ld: vmlinux.o: in function `iommufd_test':
     (.text+0x3b1cdd): undefined reference to `dma_buf_get'
     ld: (.text+0x3b1d08): undefined reference to `dma_buf_put'
     ld: (.text+0x3b2105): undefined reference to `dma_buf_export'
     ld: (.text+0x3b211f): undefined reference to `dma_buf_fd'
     ld: (.text+0x3b2e47): undefined reference to `dma_buf_move_notify'

    Add the missing select.

    Fixes: d2041f1f11dd ("iommufd/selftest: Add some tests for the dmabuf flow")
    Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
    Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig
index eae3f03629b0..7e41e3ccea75 100644
--- a/drivers/iommu/iommufd/Kconfig
+++ b/drivers/iommu/iommufd/Kconfig
@@ -42,6 +42,7 @@ config IOMMUFD_TEST
 	depends on FAULT_INJECTION
 	depends on RUNTIME_TESTING_MENU
 	depends on IOMMU_PT_AMDV1
+	select DMA_SHARED_BUFFER
 	select IOMMUFD_DRIVER
 	default n
 	help