On 10/1/2025 10:53 AM, Chao Gao wrote:
> After being installed, the new TDX Module shouldn't re-configure the
> global HKID, TDMRs or PAMTs. Instead, to preserve running TDs, it should
> import the handoff data from the old module to establish all necessary
> contexts.
>
> Once the import is done, the TDX Module update is complete, and the new
> module is ready to handle requests from the VMM and guests.
>
> Call the TDH.SYS.UPDATE SEAMCALL to import the handoff data from the old
> module.
>
> Note that the location and the format of handoff data is defined by the
> TDX Module. The new module knows where to get the handoff data and how to
> parse it. The kernel doesn't need to provide its location, format etc.
>
> Signed-off-by: Chao Gao <chao.gao@intel.com>
> Tested-by: Farrah Chen <farrah.chen@intel.com>
> ---
> arch/x86/virt/vmx/tdx/seamldr.c | 5 +++++
> arch/x86/virt/vmx/tdx/tdx.c | 16 ++++++++++++++++
> arch/x86/virt/vmx/tdx/tdx.h | 2 ++
> 3 files changed, 23 insertions(+)
>
> diff --git a/arch/x86/virt/vmx/tdx/seamldr.c b/arch/x86/virt/vmx/tdx/seamldr.c
> index 75bb650d8a16..a8ca6966beac 100644
> --- a/arch/x86/virt/vmx/tdx/seamldr.c
> +++ b/arch/x86/virt/vmx/tdx/seamldr.c
> @@ -236,6 +236,7 @@ enum tdp_state {
> TDP_SHUTDOWN,
> TDP_CPU_INSTALL,
> TDP_CPU_INIT,
> + TDP_RUN_UPDATE,
> TDP_DONE,
> };
>
> @@ -310,6 +311,10 @@ static int do_seamldr_install_module(void *params)
> case TDP_CPU_INIT:
> ret = tdx_cpu_enable();
> break;
> + case TDP_RUN_UPDATE:
> + if (primary)
> + ret = tdx_module_run_update();
> + break;
> default:
> break;
> }
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index 280c2a9f3211..7613fd16a0ce 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -1225,6 +1225,22 @@ void tdx_module_set_error(void)
> tdx_module_status = TDX_MODULE_ERROR;
> }
>
> +int tdx_module_run_update(void)
> +{
> + struct tdx_module_args args = {};
> + int ret;> +
> + ret = seamcall(TDH_SYS_UPDATE, &args);
Since it's a seamcall error, shouldn't it be u64?
> + if (ret) {
> + tdx_module_status = TDX_MODULE_ERROR;
> + pr_info("module update failed: %d\n", ret);
pr_info -> pr_err?
Also, use 0x%016llx as the format.
> + return ret;
> + }
> +
> + tdx_module_status = TDX_MODULE_INITIALIZED;
> + return 0;
> +}
> +
> static bool is_pamt_page(unsigned long phys)
> {
> struct tdmr_info_list *tdmr_list = &tdx_tdmr_list;
> diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
> index b903e479e46a..983c01c6949a 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.h
> +++ b/arch/x86/virt/vmx/tdx/tdx.h
> @@ -47,6 +47,7 @@
> #define TDH_VP_WR 43
> #define TDH_SYS_CONFIG 45
> #define TDH_SYS_SHUTDOWN 52
> +#define TDH_SYS_UPDATE 53
>
> /*
> * SEAMCALL leaf:
> @@ -122,5 +123,6 @@ struct tdmr_info_list {
> int tdx_module_shutdown(void);
> void tdx_module_set_error(void);
> int tdx_cpu_enable(void);
> +int tdx_module_run_update(void);
>
> #endif