KVM/SVM: Move vmenter.S exception fixups out of line
diff mbox series

Message ID 20210226125621.111723-1-ubizjak@gmail.com
State Accepted
Commit 7531b47c8a358405e713b8070055c365f3172d74
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Series
  • KVM/SVM: Move vmenter.S exception fixups out of line
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Commit Message

Uros Bizjak Feb. 26, 2021, 12:56 p.m. UTC
Avoid jump by moving exception fixups out of line.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
---
 arch/x86/kvm/svm/vmenter.S | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

Comments

Paolo Bonzini Feb. 26, 2021, 1:46 p.m. UTC | #1
On 26/02/21 13:56, Uros Bizjak wrote:
> Avoid jump by moving exception fixups out of line.
> 
> Cc: Sean Christopherson <seanjc@google.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
> ---
>   arch/x86/kvm/svm/vmenter.S | 35 ++++++++++++++++++++---------------
>   1 file changed, 20 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
> index 343108bf0f8c..4fa17df123cd 100644
> --- a/arch/x86/kvm/svm/vmenter.S
> +++ b/arch/x86/kvm/svm/vmenter.S
> @@ -80,15 +80,9 @@ SYM_FUNC_START(__svm_vcpu_run)
>   	/* Enter guest mode */
>   	sti
>   
> -3:	vmrun %_ASM_AX
> -	jmp 5f
> -4:	cmpb $0, kvm_rebooting
> -	jne 5f
> -	ud2
> -	_ASM_EXTABLE(3b, 4b)
> +1:	vmrun %_ASM_AX
>   
> -5:
> -	cli
> +2:	cli
>   
>   #ifdef CONFIG_RETPOLINE
>   	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
> @@ -155,6 +149,13 @@ SYM_FUNC_START(__svm_vcpu_run)
>   #endif
>   	pop %_ASM_BP
>   	ret
> +
> +3:	cmpb $0, kvm_rebooting
> +	jne 2b
> +	ud2
> +
> +	_ASM_EXTABLE(1b, 3b)
> +
>   SYM_FUNC_END(__svm_vcpu_run)
>   
>   /**
> @@ -174,18 +175,15 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
>   #endif
>   	push %_ASM_BX
>   
> -	/* Enter guest mode */
> +	/* Move @vmcb to RAX. */
>   	mov %_ASM_ARG1, %_ASM_AX
> +
> +	/* Enter guest mode */
>   	sti
>   
>   1:	vmrun %_ASM_AX
> -	jmp 3f
> -2:	cmpb $0, kvm_rebooting
> -	jne 3f
> -	ud2
> -	_ASM_EXTABLE(1b, 2b)
>   
> -3:	cli
> +2:	cli
>   
>   #ifdef CONFIG_RETPOLINE
>   	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
> @@ -205,4 +203,11 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
>   #endif
>   	pop %_ASM_BP
>   	ret
> +
> +3:	cmpb $0, kvm_rebooting
> +	jne 2b
> +	ud2
> +
> +	_ASM_EXTABLE(1b, 3b)
> +
>   SYM_FUNC_END(__svm_sev_es_vcpu_run)
> 

Queued, thanks.

Paolo

Patch
diff mbox series

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 343108bf0f8c..4fa17df123cd 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -80,15 +80,9 @@  SYM_FUNC_START(__svm_vcpu_run)
 	/* Enter guest mode */
 	sti
 
-3:	vmrun %_ASM_AX
-	jmp 5f
-4:	cmpb $0, kvm_rebooting
-	jne 5f
-	ud2
-	_ASM_EXTABLE(3b, 4b)
+1:	vmrun %_ASM_AX
 
-5:
-	cli
+2:	cli
 
 #ifdef CONFIG_RETPOLINE
 	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
@@ -155,6 +149,13 @@  SYM_FUNC_START(__svm_vcpu_run)
 #endif
 	pop %_ASM_BP
 	ret
+
+3:	cmpb $0, kvm_rebooting
+	jne 2b
+	ud2
+
+	_ASM_EXTABLE(1b, 3b)
+
 SYM_FUNC_END(__svm_vcpu_run)
 
 /**
@@ -174,18 +175,15 @@  SYM_FUNC_START(__svm_sev_es_vcpu_run)
 #endif
 	push %_ASM_BX
 
-	/* Enter guest mode */
+	/* Move @vmcb to RAX. */
 	mov %_ASM_ARG1, %_ASM_AX
+
+	/* Enter guest mode */
 	sti
 
 1:	vmrun %_ASM_AX
-	jmp 3f
-2:	cmpb $0, kvm_rebooting
-	jne 3f
-	ud2
-	_ASM_EXTABLE(1b, 2b)
 
-3:	cli
+2:	cli
 
 #ifdef CONFIG_RETPOLINE
 	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
@@ -205,4 +203,11 @@  SYM_FUNC_START(__svm_sev_es_vcpu_run)
 #endif
 	pop %_ASM_BP
 	ret
+
+3:	cmpb $0, kvm_rebooting
+	jne 2b
+	ud2
+
+	_ASM_EXTABLE(1b, 3b)
+
 SYM_FUNC_END(__svm_sev_es_vcpu_run)