The first patch ensures that the mappings needed for handling mmap operation would be managed by using the pfn instead of struct page. The second patch restores support for mapping hugetlb pages where subpages of a hugepage are not directly used anymore (main reason for revert) and instead the hugetlb pages and the relevant offsets are used to populate the scatterlist for dma-buf export and for mmap operation. Testcase: default_hugepagesz=2M hugepagesz=2M hugepages=2500 options were passed to the Host kernel and Qemu was launched with these relevant options: qemu-system-x86_64 -m 4096m.... -device virtio-gpu-pci,max_outputs=1,blob=true,xres=1920,yres=1080 -display gtk,gl=on -object memory-backend-memfd,hugetlb=on,id=mem1,size=4096M -machine memory-backend=mem1 Replacing -display gtk,gl=on with -display gtk,gl=off above would exercise the mmap handler. Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx> Cc: Dongwon Kim <dongwon.kim@xxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: James Houghton <jthoughton@xxxxxxxxxx> Cc: Jerome Marchand <jmarchan@xxxxxxxxxx> Cc: Junxiao Chang <junxiao.chang@xxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Vivek Kasireddy (2): udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap udmabuf: Add back support for mapping hugetlb pages drivers/dma-buf/udmabuf.c | 105 ++++++++++++++++++++++++++++++++------ 1 file changed, 88 insertions(+), 17 deletions(-) -- 2.39.2
