Re: [PATCH v4 16/24] x86/virt/seamldr: Install a new TDX Module

[Huang, Kai]

On Thu, 2026-02-12 at 06:35 -0800, Chao Gao wrote:
> Following the shutdown of the existing TDX Module, the update process
> continues with installing the new module. P-SEAMLDR provides the
> SEAMLDR.INSTALL SEAMCALL to perform this installation, which must be
> executed serially across all CPUs.

Nit:

Since you mentioned "serially" here, perhaps just add a sentence to mention
that it is guaranteed by the raw spinlock inside seamldr_call()?

> 
> Implement SEAMLDR.INSTALL and execute it on every CPU.
> 
> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
> Reviewed-by: Tony Lindgren <tony.lindgren@xxxxxxxxxxxxxxx>

Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>

Also a nit below ...

> ---
>  arch/x86/virt/vmx/tdx/seamldr.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/virt/vmx/tdx/seamldr.c b/arch/x86/virt/vmx/tdx/seamldr.c
> index 4e0a98404c7f..4537311780b1 100644
> --- a/arch/x86/virt/vmx/tdx/seamldr.c
> +++ b/arch/x86/virt/vmx/tdx/seamldr.c
> @@ -22,6 +22,7 @@
>  
>  /* P-SEAMLDR SEAMCALL leaf function */
>  #define P_SEAMLDR_INFO			0x8000000000000000
> +#define P_SEAMLDR_INSTALL		0x8000000000000001
>  
>  #define SEAMLDR_MAX_NR_MODULE_4KB_PAGES	496
>  #define SEAMLDR_MAX_NR_SIG_4KB_PAGES	4
> @@ -198,6 +199,7 @@ static struct seamldr_params *init_seamldr_params(const u8 *data, u32 size)
>  enum tdp_state {
>  	TDP_START,
>  	TDP_SHUTDOWN,
> +	TDP_CPU_INSTALL,
>  	TDP_DONE,
>  };
>  
> @@ -232,9 +234,10 @@ static void print_update_failure_message(void)
>   * See multi_cpu_stop() from where this multi-cpu state-machine was
>   * adopted, and the rationale for touch_nmi_watchdog()
>   */
> -static int do_seamldr_install_module(void *params)
> +static int do_seamldr_install_module(void *seamldr_params)

Nit:

IMHO such renaming is just a noise to this patch, since in patch 10/11 it's
clear that the 'params' you passed in is seamldr_params.  No?

Perhaps just name it 'seamldr_params' at patch 11?

>  {
>  	enum tdp_state newstate, curstate = TDP_START;
> +	struct tdx_module_args args = {};
>  	int cpu = smp_processor_id();
>  	bool primary;
>  	int ret = 0;
> @@ -253,6 +256,10 @@ static int do_seamldr_install_module(void *params)
>  				if (primary)
>  					ret = tdx_module_shutdown();
>  				break;
> +			case TDP_CPU_INSTALL:
> +				args.rcx = __pa(seamldr_params);
> +				ret = seamldr_call(P_SEAMLDR_INSTALL, &args);
> +				break;
>  			default:
>  				break;
>  			}