This series implements selftests targeting the feature floated by Chao via: https://lore.kernel.org/linux-mm/20220310140911.50924-1-chao.p.peng@xxxxxxxxxxxxxxx/ Below changes aim to test the fd based approach for guest private memory in context of normal (non-confidential) VMs executing on non-confidential platforms. Confidential platforms along with the confidentiality aware software stack support a notion of private/shared accesses from the confidential VMs. Generally, a bit in the GPA conveys the shared/private-ness of the access. Non-confidential platforms don't have a notion of private or shared accesses from the guest VMs. To support this notion, KVM_HC_MAP_GPA_RANGE is modified to allow marking an access from a VM within a GPA range as always shared or private. Any suggestions regarding implementing this ioctl alternatively/cleanly are appreciated. priv_memfd_test.c file adds a suite of two basic selftests to access private memory from the guest via private/shared access and checking if the contents can be leaked to/accessed by vmm via shared memory view. Test results: 1) PMPAT - PrivateMemoryPrivateAccess test passes 2) PMSAT - PrivateMemorySharedAccess test fails currently and needs more analysis to understand the reason of failure. Important - Below patch is needed to ensure host kernel crash is avoided while running these tests: https://github.com/vishals4gh/linux/commit/b9adedf777ad84af39042e9c19899600a4add68a Github link for the patches posted as part of this series: https://github.com/vishals4gh/linux/commits/priv_memfd_selftests_v1 Note that this series is dependent on Chao's v5 patches mentioned above applied on top of 5.17. Vishal Annapurve (5): x86: kvm: HACK: Allow testing of priv memfd approach selftests: kvm: Fix inline assembly for hypercall selftests: kvm: Add a basic selftest test priv memfd selftests: kvm: priv_memfd_test: Add support for memory conversion selftests: kvm: priv_memfd_test: Add shared access test arch/x86/include/uapi/asm/kvm_para.h | 1 + arch/x86/kvm/mmu/mmu.c | 9 +- arch/x86/kvm/x86.c | 16 +- include/linux/kvm_host.h | 3 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/lib/x86_64/processor.c | 2 +- tools/testing/selftests/kvm/priv_memfd_test.c | 410 ++++++++++++++++++ virt/kvm/kvm_main.c | 2 +- 8 files changed, 436 insertions(+), 8 deletions(-) create mode 100644 tools/testing/selftests/kvm/priv_memfd_test.c -- 2.35.1.1178.g4f1659d476-goog
