then the code becomes self-explanatory. i.e., you can drop the comment.
If using this, I ended up with below:
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -23,6 +23,8 @@
#define TDX_SEAMCALL_GP (TDX_SW_ERROR | X86_TRAP_GP)
#define TDX_SEAMCALL_UD (TDX_SW_ERROR | X86_TRAP_UD)
+#define TDX_SUCCESS 0
+
Hi Kirill/Dave/David,
Are you happy with this?