diff mbox series

[03/10] x86/tdx: Move FRAME_BEGIN/END to TDX_MODULE_CALL asm macro

Message ID c0206c457f366ab007ab67ca16970cc4fc562877.1689151537.git.kai.huang@intel.com (mailing list archive)
State New, archived
Headers show
Series Unify TDCALL/SEAMCALL and TDVMCALL assembly | expand

Commit Message

Huang, Kai July 12, 2023, 8:55 a.m. UTC
Currently, the TDX_MODULE_CALL asm macro and the __tdx_module_call()
take registers directly as input and a 'struct tdx_module_output' as
optional output.  This is different from the __tdx_hypercall(), which
simply uses a structure to carry all input/output.  There's no point to
leave __tdx_module_call() complicated as it is.

As a preparation to simplify the __tdx_module_call() to make it look
like __tdx_hypercall(), move FRAME_BEGIN/END and RET from the
__tdx_module_call() to the TDX_MODULE_CALL assembly macro.  This also
allows more implementation flexibility of the assembly inside the
TDX_MODULE_CALL macro, e.g., allowing putting an _ASM_EXTABLE() after
the main body of the assembly.

This is basically based on Peter's code.

Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
---
 arch/x86/coco/tdx/tdcall.S      | 3 ---
 arch/x86/virt/vmx/tdx/tdxcall.S | 5 +++++
 2 files changed, 5 insertions(+), 3 deletions(-)

Comments

Kuppuswamy Sathyanarayanan July 12, 2023, 7:57 p.m. UTC | #1
On 7/12/23 1:55 AM, Kai Huang wrote:
> Currently, the TDX_MODULE_CALL asm macro and the __tdx_module_call()
> take registers directly as input and a 'struct tdx_module_output' as
> optional output.  This is different from the __tdx_hypercall(), which
> simply uses a structure to carry all input/output.  There's no point to
> leave __tdx_module_call() complicated as it is.
> 
> As a preparation to simplify the __tdx_module_call() to make it look
> like __tdx_hypercall(), move FRAME_BEGIN/END and RET from the
> __tdx_module_call() to the TDX_MODULE_CALL assembly macro.  This also
> allows more implementation flexibility of the assembly inside the
> TDX_MODULE_CALL macro, e.g., allowing putting an _ASM_EXTABLE() after
> the main body of the assembly.
> 
> This is basically based on Peter's code.
> 
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Suggested-by: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---

Looks fine to me.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

>  arch/x86/coco/tdx/tdcall.S      | 3 ---
>  arch/x86/virt/vmx/tdx/tdxcall.S | 5 +++++
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
> index 2eca5f43734f..e5d4b7d8ecd4 100644
> --- a/arch/x86/coco/tdx/tdcall.S
> +++ b/arch/x86/coco/tdx/tdcall.S
> @@ -78,10 +78,7 @@
>   * Return status of TDCALL via RAX.
>   */
>  SYM_FUNC_START(__tdx_module_call)
> -	FRAME_BEGIN
>  	TDX_MODULE_CALL host=0
> -	FRAME_END
> -	RET
>  SYM_FUNC_END(__tdx_module_call)
>  
>  /*
> diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S
> index 3524915d8bd9..b5ab919c7fa8 100644
> --- a/arch/x86/virt/vmx/tdx/tdxcall.S
> +++ b/arch/x86/virt/vmx/tdx/tdxcall.S
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
>  #include <asm/asm-offsets.h>
> +#include <asm/frame.h>
>  #include <asm/tdx.h>
>  
>  /*
> @@ -18,6 +19,7 @@
>   *            TDX module.
>   */
>  .macro TDX_MODULE_CALL host:req
> +	FRAME_BEGIN
>  	/*
>  	 * R12 will be used as temporary storage for struct tdx_module_output
>  	 * pointer. Since R12-R15 registers are not used by TDCALL/SEAMCALL
> @@ -91,4 +93,7 @@
>  .Lno_output_struct:
>  	/* Restore the state of R12 register */
>  	pop %r12
> +
> +	FRAME_END
> +	RET
>  .endm
Isaku Yamahata July 12, 2023, 10:05 p.m. UTC | #2
On Wed, Jul 12, 2023 at 08:55:17PM +1200,
Kai Huang <kai.huang@intel.com> wrote:

> Currently, the TDX_MODULE_CALL asm macro and the __tdx_module_call()
> take registers directly as input and a 'struct tdx_module_output' as
> optional output.  This is different from the __tdx_hypercall(), which
> simply uses a structure to carry all input/output.  There's no point to
> leave __tdx_module_call() complicated as it is.
> 
> As a preparation to simplify the __tdx_module_call() to make it look
> like __tdx_hypercall(), move FRAME_BEGIN/END and RET from the
> __tdx_module_call() to the TDX_MODULE_CALL assembly macro.  This also
> allows more implementation flexibility of the assembly inside the
> TDX_MODULE_CALL macro, e.g., allowing putting an _ASM_EXTABLE() after
> the main body of the assembly.
> 
> This is basically based on Peter's code.
> 
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Suggested-by: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---
>  arch/x86/coco/tdx/tdcall.S      | 3 ---
>  arch/x86/virt/vmx/tdx/tdxcall.S | 5 +++++
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
> index 2eca5f43734f..e5d4b7d8ecd4 100644
> --- a/arch/x86/coco/tdx/tdcall.S
> +++ b/arch/x86/coco/tdx/tdcall.S
> @@ -78,10 +78,7 @@
>   * Return status of TDCALL via RAX.
>   */
>  SYM_FUNC_START(__tdx_module_call)
> -	FRAME_BEGIN
>  	TDX_MODULE_CALL host=0
> -	FRAME_END
> -	RET
>  SYM_FUNC_END(__tdx_module_call)
>  
>  /*
> diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S
> index 3524915d8bd9..b5ab919c7fa8 100644
> --- a/arch/x86/virt/vmx/tdx/tdxcall.S
> +++ b/arch/x86/virt/vmx/tdx/tdxcall.S
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
>  #include <asm/asm-offsets.h>
> +#include <asm/frame.h>
>  #include <asm/tdx.h>
>  
>  /*
> @@ -18,6 +19,7 @@
>   *            TDX module.
>   */
>  .macro TDX_MODULE_CALL host:req
> +	FRAME_BEGIN
>  	/*
>  	 * R12 will be used as temporary storage for struct tdx_module_output
>  	 * pointer. Since R12-R15 registers are not used by TDCALL/SEAMCALL
> @@ -91,4 +93,7 @@
>  .Lno_output_struct:
>  	/* Restore the state of R12 register */
>  	pop %r12
> +
> +	FRAME_END
> +	RET
>  .endm
> -- 
> 2.41.0
> 

Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
diff mbox series

Patch

diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S
index 2eca5f43734f..e5d4b7d8ecd4 100644
--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -78,10 +78,7 @@ 
  * Return status of TDCALL via RAX.
  */
 SYM_FUNC_START(__tdx_module_call)
-	FRAME_BEGIN
 	TDX_MODULE_CALL host=0
-	FRAME_END
-	RET
 SYM_FUNC_END(__tdx_module_call)
 
 /*
diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S
index 3524915d8bd9..b5ab919c7fa8 100644
--- a/arch/x86/virt/vmx/tdx/tdxcall.S
+++ b/arch/x86/virt/vmx/tdx/tdxcall.S
@@ -1,5 +1,6 @@ 
 /* SPDX-License-Identifier: GPL-2.0 */
 #include <asm/asm-offsets.h>
+#include <asm/frame.h>
 #include <asm/tdx.h>
 
 /*
@@ -18,6 +19,7 @@ 
  *            TDX module.
  */
 .macro TDX_MODULE_CALL host:req
+	FRAME_BEGIN
 	/*
 	 * R12 will be used as temporary storage for struct tdx_module_output
 	 * pointer. Since R12-R15 registers are not used by TDCALL/SEAMCALL
@@ -91,4 +93,7 @@ 
 .Lno_output_struct:
 	/* Restore the state of R12 register */
 	pop %r12
+
+	FRAME_END
+	RET
 .endm