[RFC PATCH 13/15] x86/tdx: Add __tdcall_saved() helper
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From: Zhenzhong Duan <hidden>
Date: 2026-09-24 04:11:53
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Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
The TDX Connect ABI defines TDCALL leaves that use registers up to r15 in struct tdx_module_args as input, without returning output arguments. Add __tdcall_saved() for these leaves. Signed-off-by: Zhenzhong Duan <redacted> --- arch/x86/coco/tdx/tdcall.S | 17 +++++++++++++++++ arch/x86/include/asm/shared/tdx.h | 1 + 2 files changed, 18 insertions(+)
diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
index 52d9786da308..1dca01909dee 100644
--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S@@ -44,6 +44,23 @@ SYM_FUNC_START(__tdcall_ret) TDX_MODULE_CALL host=0 ret=1 SYM_FUNC_END(__tdcall_ret) +/* + * __tdcall_saved() - Used by TDX guests to request services from the TDX + * module (does not include VMM services) using TDCALL instruction. + * + * __tdcall_saved() function ABI: + * + * @fn (RDI) - TDCALL Leaf ID, moved to RAX + * @args (RSI) - struct tdx_module_args for input + * + * All registers in @args are used as input registers. + * + * Return status of TDCALL via RAX. + */ +SYM_FUNC_START(__tdcall_saved) + TDX_MODULE_CALL host=0 saved=1 +SYM_FUNC_END(__tdcall_saved) + /* * __tdcall_saved_ret() - Used by TDX guests to request services from the * TDX module (including VMM services) using TDCALL instruction, with
diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h
index 72520f09ef3f..90f2842f4253 100644
--- a/arch/x86/include/asm/shared/tdx.h
+++ b/arch/x86/include/asm/shared/tdx.h@@ -153,6 +153,7 @@ struct tdx_module_args { /* Used to communicate with the TDX module */ u64 __tdcall(u64 fn, struct tdx_module_args *args); u64 __tdcall_ret(u64 fn, struct tdx_module_args *args); +u64 __tdcall_saved(u64 fn, struct tdx_module_args *args); u64 __tdcall_saved_ret(u64 fn, struct tdx_module_args *args); /* Used to request services from the VMM */
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2.52.0