Hello, This patchset builds upon the memfd_restricted() system call that has been discussed in the ‘KVM: mm: fd-based approach for supporting KVM’ patch series, at https://lore.kernel.org/lkml/20221202061347.1070246-1-chao.p.peng@xxxxxxxxxxxxxxx/T/#m7e944d7892afdd1d62a03a287bd488c56e377b0c The tree can be found at: https://github.com/googleprodkernel/linux-cc/tree/restrictedmem-rmfd-hugepage Following the RFC to provide mount for memfd_restricted() syscall at https://lore.kernel.org/lkml/cover.1676507663.git.ackerleytng@xxxxxxxxxx/T/#u, this patchset adds the RMFD_HUGEPAGE flag to the memfd_restricted() syscall, which will hint the kernel to use Transparent HugePages to back restrictedmem pages. This supplements the interface proposed earlier, which requires the creation of a tmpfs mount to be passed to memfd_restricted(), with a more direct per-file hint. Dependencies: + Sean’s iteration of the ‘KVM: mm: fd-based approach for supporting KVM’ patch series at https://github.com/sean-jc/linux/tree/x86/upm_base_support + Proposed fix for restrictedmem_getattr() as mentioned on the mailing list at https://lore.kernel.org/lkml/diqzzga0fv96.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ + Hugh’s patch: https://lore.kernel.org/lkml/c140f56a-1aa3-f7ae-b7d1-93da7d5a3572@xxxxxxxxxx/, which provides functionality in shmem that reads the VM_HUGEPAGE flag in key functions shmem_is_huge() and shmem_get_inode() Future work/TODOs: + man page for the memfd_restricted() syscall + Support for per file NUMA binding hints Ackerley Tng (2): mm: restrictedmem: Add flag as THP allocation hint for memfd_restricted() syscall selftests: restrictedmem: Add selftest for RMFD_HUGEPAGE include/uapi/linux/restrictedmem.h | 1 + mm/restrictedmem.c | 27 ++++++++++++------- .../restrictedmem_hugepage_test.c | 25 +++++++++++++++++ 3 files changed, 43 insertions(+), 10 deletions(-) -- 2.39.2.637.g21b0678d19-goog
