commit e3907269b34e4f488284f35716f231da7bc3e6b3
Author: Kai Huang <kai.huang@intel.com>
Date:   Thu May 23 23:17:28 2024 +1200

    x86/virt/tdx: check NO_RBP_MOD and print module version
    
    Signed-off-by: Kai Huang <kai.huang@intel.com>

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 4d6826a76f78..ffc1c27b9134 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1097,11 +1097,60 @@ static int init_tdmrs(struct tdmr_info_list *tdmr_list)
 	return 0;
 }
 
+static int check_module_compatibility(void)
+{
+	u64 tdx_features0;
+	int ret;
+
+	ret = read_sys_metadata_field(MD_FIELD_ID_TDX_FEATURES0,
+			&tdx_features0);
+
+	if (ret)
+		return ret;
+
+	if (!(tdx_features0 & TDX_FEATURES0_NO_RBP_MOD)) {
+		pr_err("NO_RBP_MOD feature is not supported\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void print_tdx_version(void)
+{
+	u64 major, minor, update, internal;
+	int ret;
+
+	ret = read_sys_metadata_field(MD_FIELD_ID_MAJOR_VERSION, &major);
+	if (ret)
+		return;
+
+	ret = read_sys_metadata_field(MD_FIELD_ID_MINOR_VERSION, &minor);
+	if (ret)
+		return;
+
+	ret = read_sys_metadata_field(MD_FIELD_ID_UPDATE_VERSION, &update);
+	if (ret)
+		return;
+
+	ret = read_sys_metadata_field(MD_FIELD_ID_INTERNAL_VERSION, &internal);
+	if (ret)
+		return;
+
+	pr_info("module verson: %u.%u.%u.%u\n",
+			(u16)major, (u16)minor, (u16)update, (u16)internal);
+}
+
 static int init_tdx_module(void)
 {
 	struct tdx_tdmr_sysinfo tdmr_sysinfo;
 	int ret;
 
+	/* Make sure TDX module meets kernel's expectation */
+	ret = check_module_compatibility();
+	if (ret)
+		goto out;
+
 	/*
 	 * To keep things simple, assume that all TDX-protected memory
 	 * will come from the page allocator.  Make sure all pages in the
@@ -1155,6 +1204,10 @@ static int init_tdx_module(void)
 	 * Lock out memory hotplug code while building it.
 	 */
 	put_online_mems();
+
+out:
+	print_tdx_version();
+
 	return ret;
 
 err_reset_pamts:
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index b701f69485d3..13ad52352e35 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -37,6 +37,14 @@
 #define MD_FIELD_ID_PAMT_2M_ENTRY_SIZE		0x9100000100000011ULL
 #define MD_FIELD_ID_PAMT_1G_ENTRY_SIZE		0x9100000100000012ULL
 
+#define MD_FIELD_ID_TDX_FEATURES0		0x0A00000300000008ULL
+#define TDX_FEATURES0_NO_RBP_MOD		BIT_ULL(18)
+
+#define MD_FIELD_ID_MINOR_VERSION		0x0800000100000003ULL
+#define MD_FIELD_ID_MAJOR_VERSION		0x0800000100000004ULL
+#define MD_FIELD_ID_UPDATE_VERSION		0x0800000100000005ULL
+#define MD_FIELD_ID_INTERNAL_VERSION		0x0800000100000006ULL
+
 /*
  * Sub-field definition of metadata field ID.
  *