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authorKai Huang <kai.huang@intel.com>2023-08-15 14:01:56 +0300
committerDave Hansen <dave.hansen@linux.intel.com>2023-09-12 02:32:23 +0300
commit03a423d40cb30e0e1cb77a801acb56ddb0bf6f5e (patch)
tree32b488fa8be8093f770682286cbfce7a44b0eedd /arch/x86/virt/vmx
parent5d092b66119d774853cc9308522620299048a662 (diff)
downloadlinux-03a423d40cb30e0e1cb77a801acb56ddb0bf6f5e.tar.xz
x86/tdx: Skip saving output regs when SEAMCALL fails with VMFailInvalid
If SEAMCALL fails with VMFailInvalid, the SEAM software (e.g., the TDX module) won't have chance to set any output register. Skip saving the output registers to the structure in this case. Also, as '.Lno_output_struct' is the very last symbol before RET, rename it to '.Lout' to make it short. Opportunistically make the asm directives unindented. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/704088f5b4d72c7e24084f7f15bd1ac5005b7213.1692096753.git.kai.huang%40intel.com
Diffstat (limited to 'arch/x86/virt/vmx')
-rw-r--r--arch/x86/virt/vmx/tdx/tdxcall.S29
1 files changed, 20 insertions, 9 deletions
diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S
index 49a54356ae99..6bdf6e137953 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
@@ -44,7 +46,7 @@
mov %rsi, %rcx
/* Leave input param 2 in RDX */
- .if \host
+.if \host
seamcall
/*
* SEAMCALL instruction is essentially a VMExit from VMX root
@@ -57,13 +59,10 @@
* 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:
-
- .else
+ jc .Lseamcall_vmfailinvalid
+.else
tdcall
- .endif
+.endif
/*
* Fetch output pointer from stack to R12 (It is used
@@ -80,7 +79,7 @@
* Other registers may contain details of the failure.
*/
test %r12, %r12
- jz .Lno_output_struct
+ jz .Lout
/* Copy result registers to output struct: */
movq %rcx, TDX_MODULE_rcx(%r12)
@@ -90,7 +89,19 @@
movq %r10, TDX_MODULE_r10(%r12)
movq %r11, TDX_MODULE_r11(%r12)
-.Lno_output_struct:
+.Lout:
/* Restore the state of R12 register */
pop %r12
+
+ FRAME_END
+ RET
+
+.if \host
+.Lseamcall_vmfailinvalid:
+ mov $TDX_SEAMCALL_VMFAILINVALID, %rax
+ /* pop the unused output pointer back to %r9 */
+ pop %r9
+ jmp .Lout
+.endif /* \host */
+
.endm