Re: [PATCH v16 12/20] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu

[Binbin Wu]

On 11/6/2026 7:46 AM, Lisa Wang wrote:
> From: Sagi Shahar <sagis@xxxxxxxxxx>
> 
> TDX VMs need to issue the KVM_TDX_INIT_VCPU ioctl for each vcpu after
> vcpu creation.
> 
> KVM_TDX_INIT_VCPU has a strict prerequisite for the CPUID state. To
> satisfy this requirement, call KVM_TDX_GET_CPUID and KVM_SET_CPUID2 to
> pull the CPUID configuration from the TDCS and commit it into KVM,
> allowing KVM_TDX_INIT_VCPU to succeed.
> 
> Additionally, unlike tdx_vm_ioctl(), tdx_vcpu_ioctl() doesn't check
> hw_error. KVM's vCPU-scoped TDX ioctl handlers don't propagate SEAMCALL
> errors into hw_error: the error is handled in the kernel and only an
> errno is returned. Checking the ioctl's return value and errno is
> therefore sufficient.
> 
> Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
> Signed-off-by: Lisa Wang <wyihan@xxxxxxxxxx>

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>

One nit below.

> ---
>  .../selftests/kvm/include/x86/tdx/tdx_util.h       | 22 ++++++++++++++++++
>  tools/testing/selftests/kvm/lib/x86/processor.c    | 27 +++++++++++++++-------
>  tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 11 +++++++++
>  3 files changed, 52 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> index 4330290d29e9..9d951f67b3b5 100644
> --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> @@ -46,9 +46,31 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
>  		    #cmd, ret, errno, strerror(errno), hw_error);	\
>  })
>  
> +#define __tdx_vcpu_ioctl(vcpu, cmd, _flags, arg)			\
> +({									\
> +	union {								\
> +		struct kvm_tdx_cmd c;					\
> +		unsigned long raw;					\
> +	} tdx_cmd = { .c = {						\
> +		.id = (cmd),						\
> +		.flags = (u32)(_flags),					\
> +		.data = (u64)(arg),					\
> +	} };								\
> +									\
> +	__vcpu_ioctl(vcpu, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd.raw);	\
> +})
> +
> +#define tdx_vcpu_ioctl(vcpu, cmd, flags, arg)				\
> +({									\
> +	int ret = __tdx_vcpu_ioctl(vcpu, cmd, flags, arg);		\
> +									\
> +	TEST_ASSERT(!ret, "%s failed, rc: %i errno: %i (%s)",		\
> +		    #cmd, ret, errno, strerror(errno));			\
> +})

Nit: missing a blank line.

>  void tdx_init_vm(struct kvm_vm *vm);