[PATCH 02/10] x86/tdx: Use cmovc to save a label in TDX_MODULE_CALL asm

[Kai Huang]

Change 'jnc .Lno_vmfailinvalid' to 'cmovc %rdi, %rax' to save the
.Lno_vmfailinvalid label in the TDX_MODULE_CALL asm macro.

Note %rdi, which is used as the first argument, has been saved to %rax
as TDCALL leaf ID thus is free to hold the error code for cmovc.

This is basically based on Peter's code.

Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
---
 arch/x86/virt/vmx/tdx/tdxcall.S | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S
index 49a54356ae99..3524915d8bd9 100644
--- a/arch/x86/virt/vmx/tdx/tdxcall.S
+++ b/arch/x86/virt/vmx/tdx/tdxcall.S
@@ -57,10 +57,8 @@
 	 * This value will never be used as actual SEAMCALL error code as
 	 * it is from the Reserved status code class.
 	 */
-	jnc .Lno_vmfailinvalid
-	mov $TDX_SEAMCALL_VMFAILINVALID, %rax
-.Lno_vmfailinvalid:
-
+	mov $TDX_SEAMCALL_VMFAILINVALID, %rdi
+	cmovc %rdi, %rax
 	.else
 	tdcall
 	.endif
-- 
2.41.0