Changes since v4 [1]: - Refactoring and fixes from comments on v4. - Rebased on Linux 6.14-rc5. The purpose of this series is to serve as a base for _restricted_ mmap() support for guest_memfd backed memory at the host [2]. It allows experimentation with what that support would be like in the safe environment of software and non-confidential VM types. For more background and for how to test this series, please refer to v2 [3]. Note that an updated version of kvmtool that works with this series is available here [4]. Cheers, /fuad [1] https://lore.kernel.org/all/20250218172500.807733-1-tabba@xxxxxxxxxx/ [2] https://lore.kernel.org/all/20250117163001.2326672-1-tabba@xxxxxxxxxx/ [3] https://lore.kernel.org/all/20250129172320.950523-1-tabba@xxxxxxxxxx/ [4] https://android-kvm.googlesource.com/kvmtool/+/refs/heads/tabba/guestmem-6.14 Fuad Tabba (9): mm: Consolidate freeing of typed folios on final folio_put() KVM: guest_memfd: Handle final folio_put() of guest_memfd pages KVM: guest_memfd: Allow host to map guest_memfd() pages KVM: guest_memfd: Handle in-place shared memory as guest_memfd backed memory KVM: x86: Mark KVM_X86_SW_PROTECTED_VM as supporting guest_memfd shared memory KVM: arm64: Refactor user_mem_abort() calculation of force_pte KVM: arm64: Handle guest_memfd()-backed guest page faults KVM: arm64: Enable mapping guest_memfd in arm64 KVM: guest_memfd: selftests: guest_memfd mmap() test when mapping is allowed arch/arm64/include/asm/kvm_host.h | 10 ++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/mmu.c | 76 ++++++++----- arch/x86/include/asm/kvm_host.h | 5 + arch/x86/kvm/Kconfig | 3 +- include/linux/kvm_host.h | 26 ++++- include/linux/page-flags.h | 31 ++++++ include/uapi/linux/kvm.h | 1 + mm/debug.c | 1 + mm/swap.c | 32 +++++- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../testing/selftests/kvm/guest_memfd_test.c | 75 ++++++++++++- virt/kvm/Kconfig | 5 + virt/kvm/guest_memfd.c | 105 ++++++++++++++++++ virt/kvm/kvm_main.c | 9 +- 15 files changed, 335 insertions(+), 46 deletions(-) base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 -- 2.48.1.711.g2feabab25a-goog