[PATCH v2 29/44] cpuidle,tdx: Make tdx noinstr clean

[Peter Zijlstra]

vmlinux.o: warning: objtool: __halt+0x2c: call to hcall_func.constprop.0() 
leaves .noinstr.text section
vmlinux.o: warning: objtool: __halt+0x3f: call to __tdx_hypercall() leaves 
.noinstr.text section
vmlinux.o: warning: objtool: __tdx_hypercall+0x66: call to 
__tdx_hypercall_failed() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 arch/x86/boot/compressed/vmlinux.lds.S |    1 +
 arch/x86/coco/tdx/tdcall.S             |    2 ++
 arch/x86/coco/tdx/tdx.c                |    5 +++--
 3 files changed, 6 insertions(+), 2 deletions(-)

--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -34,6 +34,7 @@ SECTIONS
                _text = .;      /* Text */
                *(.text)
                *(.text.*)
+               *(.noinstr.text)
                _etext = . ;
        }
        .rodata : {
--- a/arch/x86/coco/tdx/tdcall.S
+++ b/arch/x86/coco/tdx/tdcall.S
@@ -31,6 +31,8 @@
                                          TDX_R12 | TDX_R13 | \
                                          TDX_R14 | TDX_R15 )
 
+.section .noinstr.text, "ax"
+
 /*
  * __tdx_module_call()  - Used by TDX guests to request services from
  * the TDX module (does not include VMM services) using TDCALL instruction.
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -53,8 +53,9 @@ static inline u64 _tdx_hypercall(u64 fn,
 }
 
 /* Called from __tdx_hypercall() for unrecoverable failure */
-void __tdx_hypercall_failed(void)
+noinstr void __tdx_hypercall_failed(void)
 {
+       instrumentation_begin();
        panic("TDVMCALL failed. TDX module bug?");
 }
 
@@ -64,7 +65,7 @@ void __tdx_hypercall_failed(void)
  * Reusing the KVM EXIT_REASON macros makes it easier to connect the host and
  * guest sides of these calls.
  */
-static u64 hcall_func(u64 exit_reason)
+static __always_inline u64 hcall_func(u64 exit_reason)
 {
        return exit_reason;
 }