linux-kernel - [PATCH] KVM: SVM,VMX: Use %rip-relative addressing to access kvm

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Message-ID: <20231031075312.47525-1-ubizjak@gmail.com>
Date:   Tue, 31 Oct 2023 08:52:40 +0100
From:   Uros Bizjak <ubizjak@...il.com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Uros Bizjak <ubizjak@...il.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH] KVM: SVM,VMX: Use %rip-relative addressing to access kvm_rebooting

Instruction with %rip-relative address operand is one byte shorter than
its absolute address counterpart and is also compatible with position
independent executable (-fpie) build.

No functional changes intended.

Cc: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Uros Bizjak <ubizjak@...il.com>
---
 arch/x86/kvm/svm/vmenter.S | 10 +++++-----
 arch/x86/kvm/vmx/vmenter.S |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index ef2ebabb059c..9499f9c6b077 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -270,16 +270,16 @@ SYM_FUNC_START(__svm_vcpu_run)
 	RESTORE_GUEST_SPEC_CTRL_BODY
 	RESTORE_HOST_SPEC_CTRL_BODY
 
-10:	cmpb $0, kvm_rebooting
+10:	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne 2b
 	ud2
-30:	cmpb $0, kvm_rebooting
+30:	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne 4b
 	ud2
-50:	cmpb $0, kvm_rebooting
+50:	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne 6b
 	ud2
-70:	cmpb $0, kvm_rebooting
+70:	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne 8b
 	ud2
 
@@ -381,7 +381,7 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
 	RESTORE_GUEST_SPEC_CTRL_BODY
 	RESTORE_HOST_SPEC_CTRL_BODY
 
-3:	cmpb $0, kvm_rebooting
+3:	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne 2b
 	ud2
 
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index be275a0410a8..906ecd001511 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -289,7 +289,7 @@ SYM_INNER_LABEL_ALIGN(vmx_vmexit, SYM_L_GLOBAL)
 	RET
 
 .Lfixup:
-	cmpb $0, kvm_rebooting
+	cmpb $0, _ASM_RIP(kvm_rebooting)
 	jne .Lvmfail
 	ud2
 .Lvmfail:
-- 
2.41.0