Re: [PATCH v2 1/2] x86/virt/tdx: Retrieve TDX module version

Binbin Wu
2026-01-12T08:30:18Z

On 1/10/2026 3:14 AM, Vishal Verma wrote:
> From: Chao Gao <chao.gao@intel.com>
>
> Each TDX module has several bits of metadata about which specific TDX
> module it is. The primary bit of info is the version, which has an x.y.z
> format. These represent the major version, minor version, and update
> version respectively. Knowing the running TDX Module version is valuable
> for bug reporting and debugging. Note that the module does expose other
> pieces of version-related metadata, such as build number and date. Those
> aren't retrieved for now, that can be added if needed in the future.
>
> Retrieve the TDX Module version using the existing metadata reading
> interface. Later changes will expose this information. The metadata
> reading interfaces have existed for quite some time, so this will work
> with older versions of the TDX module as well - i.e. this isn't a new
> interface.
>
> As a side note, the global metadata reading code was originally set up
> to be auto-generated from a JSON definition [1]. However, later [2] this
> was found to be unsustainable, and the autogeneration approach was
> dropped in favor of just manually adding fields as needed (e.g. as in
> this patch).

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

>
> Signed-off-by: Chao Gao <chao.gao@intel.com>
> Link: https://lore.kernel.org/kvm/CABgObfYXUxqQV_FoxKjC8U3t5DnyM45nz5DpTxYZv2x_uFK_Kw@mail.gmail.com/ # [1]
> Link: https://lore.kernel.org/all/1e7bcbad-eb26-44b7-97ca-88ab53467212@intel.com/ # [2]
> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Cc: Kai Huang <kai.huang@intel.com>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Reviewed-by: Kiryl Shutsemau <kas@kernel.org>
> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> ---
> arch/x86/include/asm/tdx_global_metadata.h | 7 +++++++
> arch/x86/virt/vmx/tdx/tdx_global_metadata.c | 16 ++++++++++++++++
> 2 files changed, 23 insertions(+)
>
> diff --git a/arch/x86/include/asm/tdx_global_metadata.h b/arch/x86/include/asm/tdx_global_metadata.h
> index 060a2ad744bff..40689c8dc67eb 100644
> --- a/arch/x86/include/asm/tdx_global_metadata.h
> +++ b/arch/x86/include/asm/tdx_global_metadata.h
> @@ -5,6 +5,12 @@
>
> #include <linux/types.h>
>
> +struct tdx_sys_info_version {
> + u16 minor_version;
> + u16 major_version;
> + u16 update_version;
> +};
> +
> struct tdx_sys_info_features {
> u64 tdx_features0;
> };
> @@ -35,6 +41,7 @@ struct tdx_sys_info_td_conf {
> };
>
> struct tdx_sys_info {
> + struct tdx_sys_info_version version;
> struct tdx_sys_info_features features;
> struct tdx_sys_info_tdmr tdmr;
> struct tdx_sys_info_td_ctrl td_ctrl;
> diff --git a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
> index 13ad2663488b1..0454124803f36 100644
> --- a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
> +++ b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
> @@ -7,6 +7,21 @@
> * Include this file to other C file instead.
> */
>
> +static int get_tdx_sys_info_version(struct tdx_sys_info_version *sysinfo_version)
> +{
> + int ret = 0;
> + u64 val;
> +
> + if (!ret && !(ret = read_sys_metadata_field(0x0800000100000003, &val)))
> + sysinfo_version->minor_version = val;
> + if (!ret && !(ret = read_sys_metadata_field(0x0800000100000004, &val)))
> + sysinfo_version->major_version = val;
> + if (!ret && !(ret = read_sys_metadata_field(0x0800000100000005, &val)))
> + sysinfo_version->update_version = val;
> +
> + return ret;
> +}
> +
> static int get_tdx_sys_info_features(struct tdx_sys_info_features *sysinfo_features)
> {
> int ret = 0;
> @@ -89,6 +104,7 @@ static int get_tdx_sys_info(struct tdx_sys_info *sysinfo)
> {
> int ret = 0;
>
> + ret = ret ?: get_tdx_sys_info_version(&sysinfo->version);
> ret = ret ?: get_tdx_sys_info_features(&sysinfo->features);
> ret = ret ?: get_tdx_sys_info_tdmr(&sysinfo->tdmr);
> ret = ret ?: get_tdx_sys_info_td_ctrl(&sysinfo->td_ctrl);
>