TDX stands for Trust Domain Extensions which isolates VMs from the virtual-machine manager (VMM)/hypervisor and any other software on the platform. Intel has recently submitted a set of RFC patches for KVM support for TDX and more information can be found on the latest TDX Support Patches: https://lkml.org/lkml/2021/7/2/558 Due to the nature of the confidential computing environment that TDX provides, it is very difficult to verify/test the KVM support. TDX requires UEFI and the guest kernel to be enlightened which are all under development. We are working on a set of selftests to close this gap and be able to verify the KVM functionality to support TDX lifecycle and GHCI [1] interface. We are looking for any feedback on: - Patch series itself - Any suggestion on how we should approach testing TDX functionality. Does selftests seems reasonable or should we switch to using KVM unit tests. I would be happy to get some perspective on how KVM unit tests can help us more. - Any test case or scenario that we should add. - Anything else I have not thought of yet. Current patch series provide the following capabilities: - Provide helper functions to create a TD (Trusted Domain) using the KVM ioctls - Provide helper functions to create a guest image that can include any testing code - Provide helper functions and wrapper functions to write testing code using GHCI interface - Add a test case that verifies TDX life cycle - Add a test case that verifies TDX GHCI port IO TODOs: - Use existing function to create page tables dynamically (ie __virt_pg_map()) - Remove arbitrary defined magic numbers for data structure offsets - Add TDVMCALL for error reporting - Add additional test cases as some listed below - Add #VE handlers to help testing more complicated test cases Other test cases that we are planning to add: (with credit to sagis@xxxxxxxxxx) VM call interface Input Output Result GetTdVmCallInfo R12=0 None VMCALL_SUCCESS MapGPA Map private page (GPA.S=0) VMCALL_SUCCESS MapGPA Map shared page (GPA.S=1) VMCALL_SUCCESS MapGPA Map already private page as private VMCALL_INVALID_OPERAND MapGPA Map already shared page as shared VMCALL_INVALID_OPERAND GetQuote ReportFatalError SetupEventNotifyInterrupt Valid interrupt value (32:255) VMCALL_SUCCESS SetupEventNotifyInterrupt Invalid value (>255) VMCALL_INVALID_OPERAND Instruction.CPUID R12(EAX)=1, R13(ECX)=0 EBX[8:15]=0x8 EBX[16:23]=X EBX[24:31]=vcpu_id ECX[0]=1 ECX[12]=Y Instruction.CPUID R12(EAX)=1, R13(ECX)=4 VMCALL_INVALID_OPERAND VE.RequestMMIO Instruction.HLT VMCALL_SUCCESS Instruction.IO Read/Write 1/2/4 bytes VMCALL_SUCCESS Instruction.IO Read/Write 3 bytes VMCALL_INVALID_OPERAND Instruction.RDMSR Accessible register R11=msr_value VMCALL_SUCCESS Inaccessible register VMCALL_INVALID_OPERAND Instruction.RDMSR Accessible register VMCALL_SUCCESS Inaccessible register VMCALL_INVALID_OPERAND INSTRUCTION.PCONFIG [1] Intel TDX Guest-Hypervisor Communication Interface https://software.intel.com/content/dam/develop/external/us/en/documents/intel-tdx-guest-hypervisor-communication-interface.pdf Erdem Aktas (4): KVM: selftests: Add support for creating non-default type VMs KVM: selftest: Add helper functions to create TDX VMs KVM: selftest: Adding TDX life cycle test. KVM: selftest: Adding test case for TDX port IO tools/testing/selftests/kvm/Makefile | 6 +- .../testing/selftests/kvm/include/kvm_util.h | 1 + .../selftests/kvm/include/x86_64/processor.h | 5 + tools/testing/selftests/kvm/lib/kvm_util.c | 29 +- .../selftests/kvm/lib/x86_64/processor.c | 23 ++ tools/testing/selftests/kvm/lib/x86_64/tdx.h | 220 ++++++++++++ .../selftests/kvm/lib/x86_64/tdx_lib.c | 314 ++++++++++++++++++ .../selftests/kvm/x86_64/tdx_vm_tests.c | 209 ++++++++++++ 8 files changed, 800 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/x86_64/tdx.h create mode 100644 tools/testing/selftests/kvm/lib/x86_64/tdx_lib.c create mode 100644 tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c -- 2.32.0.432.gabb21c7263-goog
