This patch series focuses on setting up a TDX VM and adding all code necessary to run a basic lifecycle test.
Unlike standard KVM selftests can set up the VM through guest registers, TDX module protects TDs' register state from the host. This feature of TDX causes problems on VM boot state initialization and the ucall implementation. In standard KVM selftests, the host directly initializes the guest state by manipulating Special Registers (SREGs) and General Purpose Registers (GPRs) via IOCTLs (KVM_SET_SREGS, etc.) before the first KVM_RUN. To bypass direct register initialization by the host, we utilize the standard x86 reset vector as the default entry point. The mechanism works as follows: 1. The host places register values into a specific memory region and inserts boot code at the VM's default starting point. 2. When the VM starts, it executes this boot code to "pull" values from memory and manually set up its own SREGs and GPRs. 3. Once the environment is ready, the boot code jumps to the guest code. The standard x86 ucall() implementation uses PIO, but it does not actually transmit data through the 4-byte PIO data. Instead, it relies on the host reading the ucall address directly from the guest's RDI register. TDX selftests cannot utilize the standard x86 ucall implementation because the host is unable to access the guest's RDI register. Between the two alternatives, TDVMCALL_MMIO and TDVMCALL_REPORT_FATAL_ERROR, TDVMCALL_MMIO has fragility concerns and requires hardcoding a magic address while ignoring mmio_gpa. Therefore, the Report Fatal Error TDVMCALL is the cleanest and most efficient solution for TDX ucalls. Main Changes from v14[1]: 1. Include patches from Sean to transition TDX ucalls from TDVMCALL_MMIO to TDVMCALL_REPORT_FATAL_ERROR, and update the rest of the series to support this change. 2. Rename TDCALL to TDVMCALL and leaf to fn. 3. Update the commit message to clarify workflow of CPUIDs. 4. Replace manual JMP rel8 offset calculations with an assembly trampoline. Thanks review from Ackerley, Binbin, Peter, Rick, Sean and Xiaoyao ! Series is organized by: 1. Patches 1 - 3: Initialize the TDX VM 2. Patches 4 - 7: Add the TDX boot code 3. Patches 8 - 13: Set up the boot region 4. Patches 14 - 17: Set up the vCPU 5. Patches 18 - 19: Finalize the TDX VM 6. Patches 20 - 23: Implement the ucall and run the TDX test [1]: https://lore.kernel.org/all/[email protected]/ Signed-off-by: Lisa Wang <[email protected]> --- Ackerley Tng (1): KVM: selftests: Add helpers to init TDX memory and finalize VM Erdem Aktas (2): KVM: selftests: Add TDX boot code KVM: selftests: Add a helper to issue TDVMCALLs from the TDX vm Isaku Yamahata (1): KVM: selftests: Update kvm_init_vm_address_properties() for TDX Lisa Wang (3): KVM: selftests: Set shared attributes for ucall guest_memfd pages KVM: selftests: Require guest_memfd for TDX VMs KVM: selftests: Support guest_memfd in-place conversion Sagi Shahar (13): KVM: selftests: Initialize the TDX VM KVM: selftests: Expose segment definitions to assembly files tools: include: Add kbuild.h for assembly structure offsets KVM: selftests: Introduce structures for TDX guest boot parameters KVM: selftests: Expose functions to get default sregs values KVM: selftests: Set up TDX boot code region KVM: selftests: Set up TDX boot parameters region KVM: selftests: Expose function to allocate vCPU stack KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu KVM: selftests: Load per-vCPU guest stack in TDX boot parameters KVM: selftests: Set entry point for TDX guest code KVM: selftests: Finalize TDX VM in kvm_arch_vm_finalize_vcpus() KVM: selftests: Add TDX lifecycle test Sean Christopherson (3): KVM: selftests: Add macros to simplify creating VM shapes for non-default types KVM: selftests: Add support for per-VM ucall ops on x86 KVM: selftests: Add support for TDX ucalls, via TDVMCALL_REPORT_FATAL_ERROR tools/include/linux/kbuild.h | 11 + tools/testing/selftests/kvm/.gitignore | 3 +- tools/testing/selftests/kvm/Makefile.kvm | 39 ++- tools/testing/selftests/kvm/include/kvm_util.h | 27 +- .../testing/selftests/kvm/include/x86/processor.h | 44 ++++ .../selftests/kvm/include/x86/processor_asm.h | 12 + tools/testing/selftests/kvm/include/x86/sev.h | 2 - .../selftests/kvm/include/x86/tdx/td_boot.h | 81 ++++++ tools/testing/selftests/kvm/include/x86/tdx/tdx.h | 16 ++ .../selftests/kvm/include/x86/tdx/tdx_util.h | 83 ++++++ tools/testing/selftests/kvm/include/x86/ucall.h | 6 +- tools/testing/selftests/kvm/lib/kvm_util.c | 22 +- tools/testing/selftests/kvm/lib/ucall_common.c | 8 + tools/testing/selftests/kvm/lib/x86/processor.c | 147 ++++++++--- tools/testing/selftests/kvm/lib/x86/sev.c | 16 -- tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S | 71 +++++ .../selftests/kvm/lib/x86/tdx/td_boot_offsets.c | 21 ++ tools/testing/selftests/kvm/lib/x86/tdx/tdx.S | 39 +++ tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 292 +++++++++++++++++++++ tools/testing/selftests/kvm/lib/x86/ucall.c | 54 +++- tools/testing/selftests/kvm/x86/sev_dbg_test.c | 13 +- tools/testing/selftests/kvm/x86/sev_smoke_test.c | 40 +-- tools/testing/selftests/kvm/x86/tdx_vm_test.c | 33 +++ 23 files changed, 965 insertions(+), 115 deletions(-) --- base-commit: 37e0791600e5f1e2837a270c885296a172f5825e change-id: 20260722-tdx-selftests-1da5587cf047 Best regards, -- Lisa Wang <[email protected]>
