linux-kernel - [PATCH 2/8] KVM: SVM: Wrap __svm_sev_es_vcpu_run() with #ifdef CONFIG_KVM_AMD

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Date: Fri, 23 Feb 2024 12:42:27 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Tom Lendacky <thomas.lendacky@....com>, Michael Roth <michael.roth@....com>, 
	Alexey Kardashevskiy <aik@....com>
Subject: [PATCH 2/8] KVM: SVM: Wrap __svm_sev_es_vcpu_run() with #ifdef CONFIG_KVM_AMD_SEV

Compile (and link) __svm_sev_es_vcpu_run() if and only if SEV support is
actually enabled.  This will allow dropping non-existent 32-bit "support"
from __svm_sev_es_vcpu_run() without causing undue confusion.

Intentionally don't provide a stub (but keep the declaration), as any sane
compiler, even with things like KASAN enabled, should eliminate the call
to __svm_sev_es_vcpu_run() since sev_es_guest() unconditionally returns
"false" if CONFIG_KVM_AMD_SEV=n.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/vmenter.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index ee5d5a30da88..7ee363d7517c 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -291,6 +291,7 @@ SYM_FUNC_START(__svm_vcpu_run)
 
 SYM_FUNC_END(__svm_vcpu_run)
 
+#ifdef CONFIG_KVM_AMD_SEV
 /**
  * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode
  * @svm:	struct vcpu_svm *
@@ -389,3 +390,4 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
 	_ASM_EXTABLE(1b, 3b)
 
 SYM_FUNC_END(__svm_sev_es_vcpu_run)
+#endif /* CONFIG_KVM_AMD_SEV */
-- 
2.44.0.rc0.258.g7320e95886-goog