[PATCH v2 06/31] x86/virt/tdx: Read global metadata for TDX Module Extensions/Connect

Xu Yilun
2026-03-27T16:22:55Z

Add reading of the global metadata for TDX Module Extensions & TDX
Connect. Add them in a batch as TDX Connect is currently the only user
of TDX Module Extensions and no way to initialize TDX Module Extensions
without firstly enabling TDX Connect.

TDX Module Extensions & TDX Connect are optional features enumerated by
TDX_FEATURES0. Check the TDX_FEATURES0 before reading these metadata to
avoid failing the whole TDX initialization.

Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
---
arch/x86/include/asm/tdx.h | 2 ++
arch/x86/include/asm/tdx_global_metadata.h | 14 ++++++++
arch/x86/virt/vmx/tdx/tdx_global_metadata.c | 36 +++++++++++++++++++++
3 files changed, 52 insertions(+)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index d5f1d7b7d1e7..d7605235aa9b 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -129,7 +129,9 @@ int tdx_enable(void);
const char *tdx_dump_mce_info(struct mce *m);

/* Bit definitions of TDX_FEATURES0 metadata field */
+#define TDX_FEATURES0_TDXCONNECT BIT_ULL(6)
#define TDX_FEATURES0_NO_RBP_MOD BIT_ULL(18)
+#define TDX_FEATURES0_EXT BIT_ULL(39)

const struct tdx_sys_info *tdx_get_sysinfo(void);

diff --git a/arch/x86/include/asm/tdx_global_metadata.h b/arch/x86/include/asm/tdx_global_metadata.h
index 060a2ad744bf..e7948bca671a 100644
--- a/arch/x86/include/asm/tdx_global_metadata.h
+++ b/arch/x86/include/asm/tdx_global_metadata.h
@@ -34,11 +34,25 @@ struct tdx_sys_info_td_conf {
u64 cpuid_config_values[128][2];
};

+struct tdx_sys_info_ext {
+ u16 memory_pool_required_pages;
+ u8 ext_required;
+};
+
+struct tdx_sys_info_connect {
+ u16 ide_mt_page_count;
+ u16 spdm_mt_page_count;
+ u16 iommu_mt_page_count;
+ u16 spdm_max_dev_info_pages;
+};
+
struct tdx_sys_info {
struct tdx_sys_info_features features;
struct tdx_sys_info_tdmr tdmr;
struct tdx_sys_info_td_ctrl td_ctrl;
struct tdx_sys_info_td_conf td_conf;
+ struct tdx_sys_info_ext ext;
+ struct tdx_sys_info_connect connect;
};

#endif
diff --git a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
index 13ad2663488b..a07f1e7b18e8 100644
--- a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
+++ b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c
@@ -85,6 +85,36 @@ static int get_tdx_sys_info_td_conf(struct tdx_sys_info_td_conf *sysinfo_td_conf
return ret;
}

+static int get_tdx_sys_info_ext(struct tdx_sys_info_ext *sysinfo_ext)
+{
+ int ret = 0;
+ u64 val;
+
+ if (!ret && !(ret = read_sys_metadata_field(0x3100000100000000, &val)))
+ sysinfo_ext->memory_pool_required_pages = val;
+ if (!ret && !(ret = read_sys_metadata_field(0x3100000100000001, &val)))
+ sysinfo_ext->ext_required = val;
+
+ return ret;
+}
+
+static int get_tdx_sys_info_connect(struct tdx_sys_info_connect *sysinfo_connect)
+{
+ int ret = 0;
+ u64 val;
+
+ if (!ret && !(ret = read_sys_metadata_field(0x3000000100000001, &val)))
+ sysinfo_connect->ide_mt_page_count = val;
+ if (!ret && !(ret = read_sys_metadata_field(0x3000000100000002, &val)))
+ sysinfo_connect->spdm_mt_page_count = val;
+ if (!ret && !(ret = read_sys_metadata_field(0x3000000100000003, &val)))
+ sysinfo_connect->iommu_mt_page_count = val;
+ if (!ret && !(ret = read_sys_metadata_field(0x3000000100000007, &val)))
+ sysinfo_connect->spdm_max_dev_info_pages = val;
+
+ return ret;
+}
+
static int get_tdx_sys_info(struct tdx_sys_info *sysinfo)
{
int ret = 0;
@@ -94,5 +124,11 @@ static int get_tdx_sys_info(struct tdx_sys_info *sysinfo)
ret = ret ?: get_tdx_sys_info_td_ctrl(&sysinfo->td_ctrl);
ret = ret ?: get_tdx_sys_info_td_conf(&sysinfo->td_conf);

+ if (sysinfo->features.tdx_features0 & TDX_FEATURES0_EXT)
+ ret = ret ?: get_tdx_sys_info_ext(&sysinfo->ext);
+
+ if (sysinfo->features.tdx_features0 & TDX_FEATURES0_TDXCONNECT)
+ ret = ret ?: get_tdx_sys_info_connect(&sysinfo->connect);
+
return ret;
}
--
2.25.1