On 4/9/2022 2:35 AM, Vishal Annapurve wrote: > This series implements selftests targeting the feature floated by Chao > via: > https://lore.kernel.org/linux-mm/20220310140911.50924-1-chao.p.peng@xxxxxxxxxxxxxxx/ > Thanks for working on this. > 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. That could be because of the return code (*r = -1) from the KVM_EXIT_MEMORY_ERROR. This gets interpreted as -EPERM in the VMM when the vcpu_run exits. + vcpu->run->exit_reason = KVM_EXIT_MEMORY_ERROR; + vcpu->run->memory.flags = flags; + vcpu->run->memory.padding = 0; + vcpu->run->memory.gpa = fault->gfn << PAGE_SHIFT; + vcpu->run->memory.size = PAGE_SIZE; + fault->pfn = -1; + *r = -1; + return true; Regards Nikunj [1] https://lore.kernel.org/all/20220310140911.50924-10-chao.p.peng@xxxxxxxxxxxxxxx/#t
