[PATCH v2] KVM: VMX: replace "fall through" with "return" to indicate different case

[PATCH v2] KVM: VMX: replace "fall through" with "return" to indicate different case

[linmiaohe]

From: Miaohe Lin <linmiaohe@huawei.com>

The second "/* fall through */" in rmode_exception() makes code harder to
read. Replace it with "return" to indicate they are different cases, only
the #DB and #BP check vcpu->guest_debug, while others don't care. And this
also improves the readability.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 arch/x86/kvm/vmx/vmx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a13368b2719c..5b8f024f06c2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4492,10 +4492,8 @@ static bool rmode_exception(struct kvm_vcpu *vcpu, int vec)
 			return false;
 		/* fall through */
 	case DB_VECTOR:
-		if (vcpu->guest_debug &
-			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
-			return false;
-		/* fall through */
+		return !(vcpu->guest_debug &
+			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP));
 	case DE_VECTOR:
 	case OF_VECTOR:
 	case BR_VECTOR:
-- 
2.19.1

Re: [PATCH v2] KVM: VMX: replace "fall through" with "return" to indicate different case

[Paolo Bonzini]

On 19/02/20 03:45, linmiaohe wrote:
> From: Miaohe Lin <linmiaohe@huawei.com>
> 
> The second "/* fall through */" in rmode_exception() makes code harder to
> read. Replace it with "return" to indicate they are different cases, only
> the #DB and #BP check vcpu->guest_debug, while others don't care. And this
> also improves the readability.
> 
> Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index a13368b2719c..5b8f024f06c2 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -4492,10 +4492,8 @@ static bool rmode_exception(struct kvm_vcpu *vcpu, int vec)
>  			return false;
>  		/* fall through */
>  	case DB_VECTOR:
> -		if (vcpu->guest_debug &
> -			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
> -			return false;
> -		/* fall through */
> +		return !(vcpu->guest_debug &
> +			(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP));
>  	case DE_VECTOR:
>  	case OF_VECTOR:
>  	case BR_VECTOR:
> 

Queued, thanks.

Paolo