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. Based on this restriction, we used TDCALL with an 8-byte MMIO data to implement ucall. This method is the cleanest and efficient implementation for the overall ucall architecture. v14 revision for TDX KVM selftests based on kvm/next and guest_memfd: In-place conversion support[1]. This series needs some changes from in-place conversion v9. For ease of testing, an extra hack commit has been added. The complete code is available at: https://github.com/googleprodkernel/linux-cc/commits/tdx-selftests-v14 Changes from v13[2]: 1. Fixed some bugs, including typo and commit messages. 2. Outlined TDCALL from tdx.c to tdx.S. 3. Used HPET(0xfed00000) for ucall GPA address. 4. Supported guest_memfd w/wo in-place conversion support. Thanks review from Ackerley, Binbin, Chenyi, Sean and Xiaoyao! Series is organized by: 1. Patches 1 - 4: Initialize the TDX VM 2. Patches 5 - 8: Add the TDX boot code 3. Patches 9 - 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 - 22: Implement the ucall and run the TDX test [1]: https://lore.kernel.org/all/[email protected]/T/ [2]: https://lore.kernel.org/all/[email protected]/ Signed-off-by: Lisa Wang <[email protected]> --- Ackerley Tng (2): KVM: selftests: Add helpers to init TDX memory and finalize VM KVM: selftests: Add ucall support for TDX Erdem Aktas (2): KVM: selftests: Add TDX boot code KVM: selftests: Implement MMIO WRITE for the TDX VM Isaku Yamahata (2): KVM: selftests: Update kvm_init_vm_address_properties() for TDX KVM: selftests: TDX: Use KVM_TDX_CAPABILITIES to validate TDs' attribute configuration Lisa Wang (2): 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 TD memory as part of kvm_arch_vm_finalize_vcpus KVM: selftests: Add TDX lifecycle test Sean Christopherson (1): KVM: selftests: Add macros to simplify creating VM shapes for non-default types tools/include/linux/kbuild.h | 11 + tools/testing/selftests/kvm/.gitignore | 3 +- tools/testing/selftests/kvm/Makefile.kvm | 33 ++- 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 | 82 ++++++ tools/testing/selftests/kvm/include/x86/tdx/tdx.h | 17 ++ .../selftests/kvm/include/x86/tdx/tdx_util.h | 82 ++++++ 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 | 125 +++++--- tools/testing/selftests/kvm/lib/x86/sev.c | 16 -- tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S | 61 ++++ .../selftests/kvm/lib/x86/tdx/td_boot_offsets.c | 21 ++ tools/testing/selftests/kvm/lib/x86/tdx/tdx.S | 37 +++ tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 316 +++++++++++++++++++++ tools/testing/selftests/kvm/lib/x86/ucall.c | 33 +++ tools/testing/selftests/kvm/x86/sev_smoke_test.c | 40 +-- tools/testing/selftests/kvm/x86/tdx_vm_test.c | 33 +++ 22 files changed, 927 insertions(+), 104 deletions(-) --- base-commit: 2145a419fb2a4cdc8eefc8497425d2827f46e660 change-id: 20260722-tdx-selftests-1da5587cf047 Best regards, -- Lisa Wang <[email protected]>
