From: Chao Gao <chao.gao@intel.com>
Date: Wed, 20 May 2026 22:29:13 +0000 (-0700)
Subject: x86/virt/tdx: Enable TDX module runtime updates
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=1e35f5945db9630c0602d9a9a7bbd146a96d13cc;p=thirdparty%2Fkernel%2Flinux.git

x86/virt/tdx: Enable TDX module runtime updates

All pieces of TDX module runtime updates are in place. Enable it if it
is supported.

Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com>
Reviewed-by: Tony Lindgren <tony.lindgren@linux.intel.com>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://patch.msgid.link/20260520133909.409394-24-chao.gao@intel.com
---

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 5d750fe53669c..e5a9cf656c072 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -33,6 +33,7 @@
 #define TDX_RND_NO_ENTROPY	0x8000020300000000ULL
 
 /* Bit definitions of TDX_FEATURES0 metadata field */
+#define TDX_FEATURES0_TD_PRESERVING	BIT_ULL(1)
 #define TDX_FEATURES0_NO_RBP_MOD	BIT_ULL(18)
 
 #ifndef __ASSEMBLER__
@@ -113,8 +114,7 @@ const struct tdx_sys_info *tdx_get_sysinfo(void);
 
 static inline bool tdx_supports_runtime_update(const struct tdx_sys_info *sysinfo)
 {
-	/* To be enabled when kernel is ready. */
-	return false;
+	return sysinfo->features.tdx_features0 & TDX_FEATURES0_TD_PRESERVING;
 }
 
 int tdx_guest_keyid_alloc(void);