Re: [PATCH v13 08/22] KVM: selftests: Add TDX boot code

[Chenyi Qiang]

On 5/22/2026 7:16 AM, Lisa Wang wrote:
> From: Erdem Aktas <erdemaktas@xxxxxxxxxx>
> 
> Add code to boot a TDX test VM. Since TDX registers are inaccessible to
> KVM, the boot code loads the relevant values from memory into the
> registers before jumping to the guest code.
> 
> Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
> Signed-off-by: Erdem Aktas <erdemaktas@xxxxxxxxxx>
> Co-developed-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> Co-developed-by: Sagi Shahar <sagis@xxxxxxxxxx>
> Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
> Signed-off-by: Lisa Wang <wyihan@xxxxxxxxxx>
> ---
>  tools/testing/selftests/kvm/Makefile.kvm           |  1 +
>  .../selftests/kvm/include/x86/tdx/td_boot.h        |  5 ++
>  .../selftests/kvm/include/x86/tdx/td_boot_asm.h    | 16 ++++++
>  tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S  | 60 ++++++++++++++++++++++
>  4 files changed, 82 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index 02fad7b35eac..929965ca4b75 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c
>  LIBKVM_x86 += lib/x86/svm.c
>  LIBKVM_x86 += lib/x86/ucall.c
>  LIBKVM_x86 += lib/x86/vmx.c
> +LIBKVM_x86 += lib/x86/tdx/td_boot.S
>  
>  LIBKVM_arm64 += lib/arm64/gic.c
>  LIBKVM_arm64 += lib/arm64/gic_v3.c
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> index af4474dee387..e5d54a20ed72 100644
> --- a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> @@ -66,4 +66,9 @@ struct td_boot_parameters {
>  	struct td_per_vcpu_parameters per_vcpu[];
>  };
>  
> +void td_boot(void);
> +void td_boot_code_end(void);
> +
> +#define TD_BOOT_CODE_SIZE (td_boot_code_end - td_boot)
> +
>  #endif /* SELFTEST_TDX_TD_BOOT_H */
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
> new file mode 100644
> index 000000000000..10b4b527595c
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef SELFTEST_TDX_TD_BOOT_ASM_H
> +#define SELFTEST_TDX_TD_BOOT_ASM_H
> +
> +/*
> + * GPA where TD boot parameters will be loaded.
> + *
> + * TD_BOOT_PARAMETERS_GPA is arbitrarily chosen to
> + *
> + * + be within the 4GB address space
> + * + provide enough contiguous memory for the struct td_boot_parameters such
> + *   that there is one struct td_per_vcpu_parameters for KVM_MAX_VCPUS
> + */
> +#define TD_BOOT_PARAMETERS_GPA 0xffff0000
> +
> +#endif  // SELFTEST_TDX_TD_BOOT_ASM_H

It would be better to maintain consistency by using /* ... */ for single-line comments in this series, such as the SELFTESTS_TDX_TDX_H in patch 20 and other license Identifier.