[PATCH] KVM: SVM: Add exception to disable objtool warning for kvm-amd.o

[Nikunj A Dadhania <nikunj@amd.com>]

commit 7f4b5cde2409 ("kvm: Disable objtool frame pointer checking for
vmenter.S") had added the vmenter.o file to the exception list.

objtool gives the following warnings in the newer kernel builds:

  arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_vcpu_run+0x17d: BP used as a scratch register
  arch/x86/kvm/kvm-amd.o: warning: objtool: __svm_sev_es_vcpu_run+0x72: BP used as a scratch register

As kvm-amd.o is a link time object, skipping the kvm-amd.o is not possible
as per the objtool documentation, better to skip the offending functions.

Functions __svm_vcpu_run() and __svm_sev_es_vcpu_run() saves and restores
RBP. Below is the snippet:

    SYM_FUNC_START(__svm_vcpu_run)
        push %_ASM_BP
    <…>
        pop %_ASM_BP
        RET

Add exceptions to skip both these functions. Remove the
OBJECT_FILES_NON_STANDARD for vmenter.o

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Reported-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
---
 arch/x86/kvm/Makefile      | 4 ----
 arch/x86/kvm/svm/vmenter.S | 2 ++
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 80e3fe184d17..0c5c2f090e93 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -3,10 +3,6 @@
 ccflags-y += -I $(srctree)/arch/x86/kvm
 ccflags-$(CONFIG_KVM_WERROR) += -Werror
 
-ifeq ($(CONFIG_FRAME_POINTER),y)
-OBJECT_FILES_NON_STANDARD_vmenter.o := y
-endif
-
 include $(srctree)/virt/kvm/Makefile.kvm
 
 kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 8e8295e774f0..8fd37d661c33 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -289,6 +289,7 @@ SYM_FUNC_START(__svm_vcpu_run)
 	_ASM_EXTABLE(7b, 70b)
 
 SYM_FUNC_END(__svm_vcpu_run)
+STACK_FRAME_NON_STANDARD(__svm_vcpu_run)
 
 /**
  * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode
@@ -388,3 +389,4 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
 	_ASM_EXTABLE(1b, 3b)
 
 SYM_FUNC_END(__svm_sev_es_vcpu_run)
+STACK_FRAME_NON_STANDARD_FP(__svm_sev_es_vcpu_run)
-- 
2.34.1