2023-10-31 07:54:00

by Uros Bizjak

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 <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Signed-off-by: Uros Bizjak <[email protected]>
---
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

2023-12-01 01:55:38

by Sean Christopherson

Subject: Re: [PATCH] KVM: SVM,VMX: Use %rip-relative addressing to access kvm_rebooting

On Tue, 31 Oct 2023 08:52:40 +0100, Uros Bizjak wrote:
> 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.
>
>
> [...]

Applied to kvm-x86 misc, thanks!

[1/1] KVM: SVM,VMX: Use %rip-relative addressing to access kvm_rebooting
https://github.com/kvm-x86/linux/commit/15223c4f973a

--
https://github.com/kvm-x86/linux/tree/next