Re: [PATCH 03/15] x86/virt/tdx: Make TDX Module initialize Extensions

[Xiaoyao Li]

On 5/22/2026 11:41 AM, Xu Yilun wrote:
> After providing all required memory to TDX Module, initialize TDX
> Module Extensions via TDH.EXT.INIT, so Extension-SEAMCALLs can be used.
>
> Co-developed-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
> Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx>

Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>

> ---
>   arch/x86/virt/vmx/tdx/tdx.h |  1 +
>   arch/x86/virt/vmx/tdx/tdx.c | 24 +++++++++++++++++++++++-
>   2 files changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
> index 2335f88bbb10..c5bffd118145 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.h
> +++ b/arch/x86/virt/vmx/tdx/tdx.h
> @@ -46,6 +46,7 @@
>   #define TDH_PHYMEM_PAGE_WBINVD		41
>   #define TDH_VP_WR			43
>   #define TDH_SYS_CONFIG			45
> +#define TDH_EXT_INIT			60
>   #define TDH_EXT_MEM_ADD			61
>   #define TDH_SYS_DISABLE			69
>   
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index 622399d8da68..ff2b96c20d2b 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -1200,6 +1200,22 @@ static u64 to_hpa_list_info(struct page *root, unsigned int nr_pages)
>   	       FIELD_PREP(HPA_LIST_INFO_LAST_ENTRY, nr_pages - 1);
>   }
>   
> +/* Initialize the TDX Module Extensions then Extension-SEAMCALLs can be used */
> +static int tdx_ext_init(void)
> +{
> +	struct tdx_module_args args = {};
> +	u64 r;
> +
> +	do {
> +		r = seamcall(TDH_EXT_INIT, &args);
> +	} while (r == TDX_INTERRUPTED_RESUMABLE);
> +
> +	if (r != TDX_SUCCESS)
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
>   static int tdx_ext_mem_add(struct page *root, unsigned int nr_pages)
>   {
>   	struct tdx_module_args args = {
> @@ -1287,6 +1303,8 @@ static int tdx_ext_mem_setup(void)
>   
>   static int __maybe_unused init_tdx_ext(void)
>   {
> +	int ret;
> +
>   	if (!(tdx_sysinfo.features.tdx_features0 & TDX_FEATURES0_EXT))
>   		return 0;
>   
> @@ -1294,7 +1312,11 @@ static int __maybe_unused init_tdx_ext(void)
>   	if (!tdx_sysinfo.ext.ext_required)
>   		return 0;
>   
> -	return tdx_ext_mem_setup();
> +	ret = tdx_ext_mem_setup();
> +	if (ret)
> +		return ret;
> +
> +	return tdx_ext_init();
>   }
>   
>   static __init int init_tdx_module(void)